2024-03-29T02:25:36Zhttp://repository.helmholtz-hzi.de/oai/requestoai:repository.helmholtz-hzi.de:10033/2006692019-08-30T11:30:31Zcom_10033_620656col_10033_620657
Xu, Kuiying
Wetzel, Marie
W. Hartmann, Rolf
Marchais-Oberwinkler, Sandrine
2012-01-06T08:51:56Z
2012-01-06T08:51:56Z
2012-01-06T08:51:56Z
Synthesis and Biological Evaluation of Spiro-δ-lactones as Inhibitors of 17β-Hydroxysteroid Dehydrogenase Type 2 (17β-HSD2) 2011, 8 (5):406 Letters in Drug Design & Discovery
15701808
10.2174/157018011795514230
http://hdl.handle.net/10033/200669
Letters in Drug Design & Discovery
http://openurl.ingenta.com/content/xref?genre=article&issn=1570-1808&volume=8&issue=5&spage=406
Synthesis and Biological Evaluation of Spiro-δ-lactones as Inhibitors of 17β-Hydroxysteroid Dehydrogenase Type 2 (17β-HSD2)
Article2012-06-15T00:00:00Zoai:repository.helmholtz-hzi.de:10033/2039492019-08-30T11:25:43Zcom_10033_620656col_10033_620657
Klein, Tobias
Henn, Claudia
Negri, Matthias
Frotscher, Martin
Pharmaceutical and Medicinal Chemistry, Saarland University, Saarbrücken, Germany.
2012-01-20T13:41:17Z
2012-01-20T13:41:17Z
2011
Structural basis for species specific inhibition of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1): computational study and biological validation. 2011, 6 (8):e22990 PLoS ONE
1932-6203
21857977
10.1371/journal.pone.0022990
http://hdl.handle.net/10033/203949
PloS one
17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the reduction of estrone to estradiol, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 and thereby reducing the intracellular estradiol concentration is thus a promising approach for the treatment of estrogen dependent diseases. In the past, several steroidal and non-steroidal inhibitors of 17β-HSD1 have been described but so far there is no cocrystal structure of the latter in complex with 17β-HSD1. However, a distinct knowledge of active site topologies and protein-ligand interactions is a prerequisite for structure-based drug design and optimization. An elegant strategy to enhance this knowledge is to compare inhibition values obtained for one compound toward ortholog proteins from various species, which are highly conserved in sequence and differ only in few residues. In this study the inhibitory potencies of selected members of different non-steroidal inhibitor classes toward marmoset 17β-HSD1 were determined and the data were compared with the values obtained for the human enzyme. A species specific inhibition profile was observed in the class of the (hydroxyphenyl)naphthols. Using a combination of computational methods, including homology modelling, molecular docking, MD simulation, and binding energy calculation, a reasonable model of the three-dimensional structure of marmoset 17β-HSD1 was developed and inhibition data were rationalized on the structural basis. In marmoset 17β-HSD1, residues 190 to 196 form a small α-helix, which induces conformational changes compared to the human enzyme. The docking poses suggest these conformational changes as determinants for species specificity and energy decomposition analysis highlighted the outstanding role of Asn152 as interaction partner for inhibitor binding. In summary, this strategy of comparing the biological activities of inhibitors toward highly conserved ortholog proteins might be an alternative to laborious x-ray or site-directed mutagenesis experiments in certain cases. Additionally, it facilitates inhibitor design and optimization by offering new information on protein-ligand interactions.
en
Structural basis for species specific inhibition of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1): computational study and biological validation.
Article2018-06-13T00:49:28Z17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the reduction of estrone to estradiol, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 and thereby reducing the intracellular estradiol concentration is thus a promising approach for the treatment of estrogen dependent diseases. In the past, several steroidal and non-steroidal inhibitors of 17β-HSD1 have been described but so far there is no cocrystal structure of the latter in complex with 17β-HSD1. However, a distinct knowledge of active site topologies and protein-ligand interactions is a prerequisite for structure-based drug design and optimization. An elegant strategy to enhance this knowledge is to compare inhibition values obtained for one compound toward ortholog proteins from various species, which are highly conserved in sequence and differ only in few residues. In this study the inhibitory potencies of selected members of different non-steroidal inhibitor classes toward marmoset 17β-HSD1 were determined and the data were compared with the values obtained for the human enzyme. A species specific inhibition profile was observed in the class of the (hydroxyphenyl)naphthols. Using a combination of computational methods, including homology modelling, molecular docking, MD simulation, and binding energy calculation, a reasonable model of the three-dimensional structure of marmoset 17β-HSD1 was developed and inhibition data were rationalized on the structural basis. In marmoset 17β-HSD1, residues 190 to 196 form a small α-helix, which induces conformational changes compared to the human enzyme. The docking poses suggest these conformational changes as determinants for species specificity and energy decomposition analysis highlighted the outstanding role of Asn152 as interaction partner for inhibitor binding. In summary, this strategy of comparing the biological activities of inhibitors toward highly conserved ortholog proteins might be an alternative to laborious x-ray or site-directed mutagenesis experiments in certain cases. Additionally, it facilitates inhibitor design and optimization by offering new information on protein-ligand interactions.oai:repository.helmholtz-hzi.de:10033/2146512019-08-30T11:26:42Zcom_10033_620656col_10033_620657
Klein, Tobias
Henn, Claudia
Negri, Matthias
Frotscher, Martin
Pharmaceutical and Medicinal Chemistry, Saarland University, Saarbrücken, Germany.
2012-03-07T15:35:23Z
2012-03-07T15:35:23Z
2011
Structural basis for species specific inhibition of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1): computational study and biological validation. 2011, 6 (8):e22990 PLoS ONE
1932-6203
21857977
10.1371/journal.pone.0022990
http://hdl.handle.net/10033/214651
PloS one
17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the reduction of estrone to estradiol, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 and thereby reducing the intracellular estradiol concentration is thus a promising approach for the treatment of estrogen dependent diseases. In the past, several steroidal and non-steroidal inhibitors of 17β-HSD1 have been described but so far there is no cocrystal structure of the latter in complex with 17β-HSD1. However, a distinct knowledge of active site topologies and protein-ligand interactions is a prerequisite for structure-based drug design and optimization. An elegant strategy to enhance this knowledge is to compare inhibition values obtained for one compound toward ortholog proteins from various species, which are highly conserved in sequence and differ only in few residues. In this study the inhibitory potencies of selected members of different non-steroidal inhibitor classes toward marmoset 17β-HSD1 were determined and the data were compared with the values obtained for the human enzyme. A species specific inhibition profile was observed in the class of the (hydroxyphenyl)naphthols. Using a combination of computational methods, including homology modelling, molecular docking, MD simulation, and binding energy calculation, a reasonable model of the three-dimensional structure of marmoset 17β-HSD1 was developed and inhibition data were rationalized on the structural basis. In marmoset 17β-HSD1, residues 190 to 196 form a small α-helix, which induces conformational changes compared to the human enzyme. The docking poses suggest these conformational changes as determinants for species specificity and energy decomposition analysis highlighted the outstanding role of Asn152 as interaction partner for inhibitor binding. In summary, this strategy of comparing the biological activities of inhibitors toward highly conserved ortholog proteins might be an alternative to laborious x-ray or site-directed mutagenesis experiments in certain cases. Additionally, it facilitates inhibitor design and optimization by offering new information on protein-ligand interactions.
en
Amino Acid Sequence
Amino Acids
Animals
Binding Sites
Callithrix
Computer Simulation
Crystallography, X-Ray
Enzyme Inhibitors
Estradiol Dehydrogenases
Humans
Kinetics
Models, Molecular
Molecular Sequence Data
Molecular Structure
Protein Binding
Protein Structure, Tertiary
Sequence Homology, Amino Acid
Species Specificity
Structure-Activity Relationship
Substrate Specificity
Structural basis for species specific inhibition of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1): computational study and biological validation.
Article2018-06-12T21:42:12Z17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the reduction of estrone to estradiol, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 and thereby reducing the intracellular estradiol concentration is thus a promising approach for the treatment of estrogen dependent diseases. In the past, several steroidal and non-steroidal inhibitors of 17β-HSD1 have been described but so far there is no cocrystal structure of the latter in complex with 17β-HSD1. However, a distinct knowledge of active site topologies and protein-ligand interactions is a prerequisite for structure-based drug design and optimization. An elegant strategy to enhance this knowledge is to compare inhibition values obtained for one compound toward ortholog proteins from various species, which are highly conserved in sequence and differ only in few residues. In this study the inhibitory potencies of selected members of different non-steroidal inhibitor classes toward marmoset 17β-HSD1 were determined and the data were compared with the values obtained for the human enzyme. A species specific inhibition profile was observed in the class of the (hydroxyphenyl)naphthols. Using a combination of computational methods, including homology modelling, molecular docking, MD simulation, and binding energy calculation, a reasonable model of the three-dimensional structure of marmoset 17β-HSD1 was developed and inhibition data were rationalized on the structural basis. In marmoset 17β-HSD1, residues 190 to 196 form a small α-helix, which induces conformational changes compared to the human enzyme. The docking poses suggest these conformational changes as determinants for species specificity and energy decomposition analysis highlighted the outstanding role of Asn152 as interaction partner for inhibitor binding. In summary, this strategy of comparing the biological activities of inhibitors toward highly conserved ortholog proteins might be an alternative to laborious x-ray or site-directed mutagenesis experiments in certain cases. Additionally, it facilitates inhibitor design and optimization by offering new information on protein-ligand interactions.oai:repository.helmholtz-hzi.de:10033/2142382019-08-30T11:36:32Zcom_10033_620656col_10033_620657
Bihrer, Verena
Friedrich-Rust, Mireen
Kronenberger, Bernd
Forestier, Nicole
Haupenthal, Jörg
Shi, Ying
Peveling-Oberhag, Jan
Radeke, Heinfried H
Sarrazin, Christoph
Herrmann, Eva
Zeuzem, Stefan
Waidmann, Oliver
Piiper, Albrecht
Department of Medicine I, University of Frankfurt/M., Frankfurt, Germany.
2012-03-05T14:52:18Z
2012-03-05T14:52:18Z
2011-09
Serum miR-122 as a biomarker of necroinflammation in patients with chronic hepatitis C virus infection. 2011, 106 (9):1663-9 Am. J. Gastroenterol.
1572-0241
21606975
10.1038/ajg.2011.161
http://hdl.handle.net/10033/214238
The American journal of gastroenterology
The liver contains large amounts of microRNA-122 (miR-122), whereas other tissues contain only marginal amounts of this miRNA. MicroRNAs have also been found to circulate in the blood in a cell-free form; their potential as readily accessible disease markers is currently evaluated. Here, we investigated if the serum levels of miR-122 might be useful as disease parameter in patients with chronic hepatitis C virus (HCV) infection.
en
Adult
Aged
Alanine Transaminase
Aspartate Aminotransferases
Bilirubin
Biological Markers
Female
Hepatitis C, Chronic
Humans
International Normalized Ratio
Liver
Male
MicroRNAs
Middle Aged
Necrosis
Serum Albumin
Serum miR-122 as a biomarker of necroinflammation in patients with chronic hepatitis C virus infection.
Article2012-03-15T00:00:00ZThe liver contains large amounts of microRNA-122 (miR-122), whereas other tissues contain only marginal amounts of this miRNA. MicroRNAs have also been found to circulate in the blood in a cell-free form; their potential as readily accessible disease markers is currently evaluated. Here, we investigated if the serum levels of miR-122 might be useful as disease parameter in patients with chronic hepatitis C virus (HCV) infection.oai:repository.helmholtz-hzi.de:10033/2163012019-08-30T11:26:13Zcom_10033_620656col_10033_620657
Negri, Matthias
Recanatini, Maurizio
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University and Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C2.3, 66123 Saarbrücken, Germany.
2012-03-22T15:11:27Z
2012-03-22T15:11:27Z
2011-09
Computational investigation of the binding mode of bis(hydroxylphenyl)arenes in 17β-HSD1: molecular dynamics simulations, MM-PBSA free energy calculations, and molecular electrostatic potential maps. 2011, 25 (9):795-811 J. Comput. Aided Mol. Des.
1573-4951
21822722
10.1007/s10822-011-9464-7
http://hdl.handle.net/10033/216301
Journal of computer-aided molecular design
17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the last step of the estrogen biosynthesis, namely the reduction of estrone to the biologically potent estradiol. As such it is a potentially attractive drug target for the treatment of estrogen-dependent diseases like breast cancer and endometriosis. 17β-HSD1 belongs to the bisubstrate enzymes and exists as an ensemble of conformations. These principally differ in the region of the βFαG'-loop, suggesting a prominent role in substrate and inhibitor binding. Although several classes of potent non-steroidal 17β-HSD1 inhibitors currently exist, their binding mode is still unclear. We aimed to elucidate the binding mode of bis(hydroxyphenyl)arenes, a highly potent class of 17β-HSD1 inhibitors, and to rank these compounds correctly with respect to their inhibitory potency, two essential aspects in drug design. Ensemble docking experiments resulted in a steroidal binding mode for the closed enzyme conformations and in an alternative mode for the opened and occluded conformers with the inhibitors placed below the NADPH interacting with it synergically via π-π stacking and H-bond formation. Both binding modes were investigated by MD simulations and MM-PBSA binding free energy estimations using as representative member for this class compound 1 (50 nM). Notably, only the alternative binding mode proved stable and was energetically more favorable, while when simulated in the steroidal binding mode compound 1 was displaced from the active site. In parallel, ab initio studies of small NADPH-inhibitor complexes were performed, which supported the importance of the synergistic interaction between inhibitors and cofactor.
en
Archived with thanks to Journal of computer-aided molecular design
17-Hydroxysteroid Dehydrogenases
Binding Sites
Drug Design
Enzyme Inhibitors
Humans
Molecular Dynamics Simulation
Protein Binding
Static Electricity
Thermodynamics
Computational investigation of the binding mode of bis(hydroxylphenyl)arenes in 17β-HSD1: molecular dynamics simulations, MM-PBSA free energy calculations, and molecular electrostatic potential maps.
Article2018-06-12T16:56:15Z17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the last step of the estrogen biosynthesis, namely the reduction of estrone to the biologically potent estradiol. As such it is a potentially attractive drug target for the treatment of estrogen-dependent diseases like breast cancer and endometriosis. 17β-HSD1 belongs to the bisubstrate enzymes and exists as an ensemble of conformations. These principally differ in the region of the βFαG'-loop, suggesting a prominent role in substrate and inhibitor binding. Although several classes of potent non-steroidal 17β-HSD1 inhibitors currently exist, their binding mode is still unclear. We aimed to elucidate the binding mode of bis(hydroxyphenyl)arenes, a highly potent class of 17β-HSD1 inhibitors, and to rank these compounds correctly with respect to their inhibitory potency, two essential aspects in drug design. Ensemble docking experiments resulted in a steroidal binding mode for the closed enzyme conformations and in an alternative mode for the opened and occluded conformers with the inhibitors placed below the NADPH interacting with it synergically via π-π stacking and H-bond formation. Both binding modes were investigated by MD simulations and MM-PBSA binding free energy estimations using as representative member for this class compound 1 (50 nM). Notably, only the alternative binding mode proved stable and was energetically more favorable, while when simulated in the steroidal binding mode compound 1 was displaced from the active site. In parallel, ab initio studies of small NADPH-inhibitor complexes were performed, which supported the importance of the synergistic interaction between inhibitors and cofactor.oai:repository.helmholtz-hzi.de:10033/2371532019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Bihrer, Verena
Waidmann, Oliver
Friedrich-Rust, Mireen
Forestier, Nicole
Susser, Simone
Haupenthal, Jörg
Welker, Martin
Shi, Ying
Peveling-Oberhag, Jan
Polta, Andreas
von Wagner, Michael
Radeke, Heinfried H
Sarrazin, Christoph
Trojan, Jörg
Zeuzem, Stefan
Kronenberger, Bernd
Piiper, Albrecht
Department of Medicine I, University of Frankfurt/M., Frankfurt, Germany.
2012-08-03T12:25:14Z
2012-08-03T12:25:14Z
2011
Serum microRNA-21 as marker for necroinflammation in hepatitis C patients with and without hepatocellular carcinoma. 2011, 6 (10):e26971 PLoS ONE
1932-6203
22066022
10.1371/journal.pone.0026971
http://hdl.handle.net/10033/237153
PloS one
MicroRNA-21 (miR-21) is up-regulated in tumor tissue of patients with malignant diseases, including hepatocellular carcinoma (HCC). Elevated concentrations of miR-21 have also been found in sera or plasma from patients with malignancies, rendering it an interesting candidate as serum/plasma marker for malignancies. Here we correlated serum miR-21 levels with clinical parameters in patients with different stages of chronic hepatitis C virus infection (CHC) and CHC-associated HCC.
en
Archived with thanks to PloS one
Alanine Transaminase
Aspartate Aminotransferases
Bilirubin
Biological Markers
Carcinoma, Hepatocellular
Cohort Studies
Female
Hepatitis C, Chronic
Humans
Inflammation
Liver Neoplasms
Male
MicroRNAs
Middle Aged
Multivariate Analysis
Necrosis
Reproducibility of Results
Serum Albumin
gamma-Glutamyltransferase
Serum microRNA-21 as marker for necroinflammation in hepatitis C patients with and without hepatocellular carcinoma.
Article2018-06-13T03:46:56ZMicroRNA-21 (miR-21) is up-regulated in tumor tissue of patients with malignant diseases, including hepatocellular carcinoma (HCC). Elevated concentrations of miR-21 have also been found in sera or plasma from patients with malignancies, rendering it an interesting candidate as serum/plasma marker for malignancies. Here we correlated serum miR-21 levels with clinical parameters in patients with different stages of chronic hepatitis C virus infection (CHC) and CHC-associated HCC.oai:repository.helmholtz-hzi.de:10033/2375552019-08-30T11:30:32Zcom_10033_620656col_10033_620657
Lu, Cenbin
Kirsch, Benjamin
Zimmer, Christina
de Jong, Johannes C
Henn, Claudia
Maurer, Christine K
Müsken, Mathias
Häussler, Susanne
Steinbach, Anke
Hartmann, Rolf W
Helmholtz Institute for Pharmaceutical Research Saarland, Campus C2.3, 66123 Saarbrücken, Germany.
2012-08-07T13:35:08Z
2012-08-07T13:35:08Z
2012-03-23
Discovery of antagonists of PqsR, a key player in 2-alkyl-4-quinolone-dependent quorum sensing in Pseudomonas aeruginosa. 2012, 19 (3):381-90 Chem. Biol.
1879-1301
22444593
10.1016/j.chembiol.2012.01.015
http://hdl.handle.net/10033/237555
Chemistry & biology
The pqs quorum sensing communication system of Pseudomonas aeruginosa controls virulence factor production and is involved in biofilm formation, therefore playing an important role for pathogenicity. In order to attenuate P. aeruginosa pathogenicity, we followed a ligand-based drug design approach and synthesized a series of compounds targeting PqsR, the receptor of the pqs system. In vitro evaluation using a reporter gene assay in Escherichia coli led to the discovery of the first competitive PqsR antagonists, which are highly potent (K(d,app) of compound 20: 7 nM). These antagonists are able to reduce the production of the virulence factor pyocyanin in P. aeruginosa. Our finding offers insights into the ligand-receptor interaction of PqsR and provides a promising starting point for further drug design.
en
Archived with thanks to Chemistry & biology
4-Quinolones
Bacterial Proteins
Drug Design
Genes, Reporter
Kinetics
Pseudomonas aeruginosa
Pyocyanine
Quorum Sensing
Discovery of antagonists of PqsR, a key player in 2-alkyl-4-quinolone-dependent quorum sensing in Pseudomonas aeruginosa.
Article2018-06-13T07:19:15ZThe pqs quorum sensing communication system of Pseudomonas aeruginosa controls virulence factor production and is involved in biofilm formation, therefore playing an important role for pathogenicity. In order to attenuate P. aeruginosa pathogenicity, we followed a ligand-based drug design approach and synthesized a series of compounds targeting PqsR, the receptor of the pqs system. In vitro evaluation using a reporter gene assay in Escherichia coli led to the discovery of the first competitive PqsR antagonists, which are highly potent (K(d,app) of compound 20: 7 nM). These antagonists are able to reduce the production of the virulence factor pyocyanin in P. aeruginosa. Our finding offers insights into the ligand-receptor interaction of PqsR and provides a promising starting point for further drug design.oai:repository.helmholtz-hzi.de:10033/2462112019-08-30T11:25:11Zcom_10033_620656col_10033_620657
Bansal, Ranju
Guleria, Sheetal
Thota, Sridhar
Bodhankar, Subhash L
Patwardhan, Moreshwar R
Zimmer, Christina
Hartmann, Rolf W
Harvey, Alan L
University Institute of Pharmaceutical Sciences, Sector-14, Panjab University, Chandigarh 160014, India. ranju29in@yahoo.co.in
2012-09-28T08:27:23Z
2012-09-28T08:27:23Z
2012-05
Design, synthesis and evaluation of novel 16-imidazolyl substituted steroidal derivatives possessing potent diversified pharmacological properties. 2012, 77 (6):621-9 Steroids
1878-5867
22366075
10.1016/j.steroids.2012.02.005
http://hdl.handle.net/10033/246211
Steroids
As a part of our investigations into the structural-activity relationship studies of a novel class of medicinally active 16-substituted steroids, several new 16-imidazolyl substituted steroidal derivatives have been synthesized and pharmacologically evaluated in the current study. The new steroidal analogues 5, 6, 8, 9, 11 and 12 exhibited moderate cytotoxic effects in sixty cancer cell lines derived from nine cancers types. The imidazolyl substituted steroidal derivatives 6 (DPJ-RG-1241) and 7 (RB-401) were obtained as the powerful inhibitors of aromatase with IC50=0.18 μM and IC50=0.168 μM, respectively, approximately 1.2 and 1.4 times more potent in comparison to standard drug exemestane. The bis-quaternary steroids 13 and 14 displayed potent skeletal muscle relaxant properties. An affinity constant of 0.007 μM was observed for compound 14 on frog rectus abdominis muscle preparation and 13 displayed a very high anticholinesterase activity K(i)=25 nM, approximately 115-fold higher in comparison to standard drug galanthamine (K(i)=2.9 μM).
en
Archived with thanks to Steroids
Antineoplastic Agents
Aromatase Inhibitors
Cell Line, Tumor
Cell Proliferation
Chemistry Techniques, Synthetic
Drug Design
Humans
Imidazoles
Inhibitory Concentration 50
Steroids
Design, synthesis and evaluation of novel 16-imidazolyl substituted steroidal derivatives possessing potent diversified pharmacological properties.
Article2018-06-13T04:24:17ZAs a part of our investigations into the structural-activity relationship studies of a novel class of medicinally active 16-substituted steroids, several new 16-imidazolyl substituted steroidal derivatives have been synthesized and pharmacologically evaluated in the current study. The new steroidal analogues 5, 6, 8, 9, 11 and 12 exhibited moderate cytotoxic effects in sixty cancer cell lines derived from nine cancers types. The imidazolyl substituted steroidal derivatives 6 (DPJ-RG-1241) and 7 (RB-401) were obtained as the powerful inhibitors of aromatase with IC50=0.18 μM and IC50=0.168 μM, respectively, approximately 1.2 and 1.4 times more potent in comparison to standard drug exemestane. The bis-quaternary steroids 13 and 14 displayed potent skeletal muscle relaxant properties. An affinity constant of 0.007 μM was observed for compound 14 on frog rectus abdominis muscle preparation and 13 displayed a very high anticholinesterase activity K(i)=25 nM, approximately 115-fold higher in comparison to standard drug galanthamine (K(i)=2.9 μM).oai:repository.helmholtz-hzi.de:10033/2493562019-08-30T11:27:46Zcom_10033_620656col_10033_620657
Spadaro, Alessandro
Negri, Matthias
Marchais-Oberwinkler, Sandrine
Bey, Emmanuel
Frotscher, Martin
Pharmaceutical and Medicinal Chemistry, Saarland University, Saarbrücken, Germany.
2012-10-18T11:35:47Z
2012-10-18T11:35:47Z
2012
Hydroxybenzothiazoles as new nonsteroidal inhibitors of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). 2012, 7 (1):e29252 PLoS ONE
1932-6203
22242164
10.1371/journal.pone.0029252
http://hdl.handle.net/10033/249356
PloS one
17β-estradiol (E2), the most potent estrogen in humans, known to be involved in the development and progession of estrogen-dependent diseases (EDD) like breast cancer and endometriosis. 17β-HSD1, which catalyses the reduction of the weak estrogen estrone (E1) to E2, is often overexpressed in breast cancer and endometriotic tissues. An inhibition of 17β-HSD1 could selectively reduce the local E2-level thus allowing for a novel, targeted approach in the treatment of EDD. Continuing our search for new nonsteroidal 17β-HSD1 inhibitors, a novel pharmacophore model was derived from crystallographic data and used for the virtual screening of a small library of compounds. Subsequent experimental verification of the virtual hits led to the identification of the moderately active compound 5. Rigidification and further structure modifications resulted in the discovery of a novel class of 17β-HSD1 inhibitors bearing a benzothiazole-scaffold linked to a phenyl ring via keto- or amide-bridge. Their putative binding modes were investigated by correlating their biological data with features of the pharmacophore model. The most active keto-derivative 6 shows IC₅₀-values in the nanomolar range for the transformation of E1 to E2 by 17β-HSD1, reasonable selectivity against 17β-HSD2 but pronounced affinity to the estrogen receptors (ERs). On the other hand, the best amide-derivative 21 shows only medium 17β-HSD1 inhibitory activity at the target enzyme as well as fair selectivity against 17β-HSD2 and ERs. The compounds 6 and 21 can be regarded as first benzothiazole-type 17β-HSD1 inhibitors for the development of potential therapeutics.
en
Archived with thanks to PloS one
17-Hydroxysteroid Dehydrogenases
Cell Line, Tumor
Crystallization
Enzyme Inhibitors
Estrogen Receptor alpha
Estrogen Receptor beta
Estrogens, Non-Steroidal
Humans
Ligands
Models, Molecular
Structure-Activity Relationship
Thiazoles
Hydroxybenzothiazoles as new nonsteroidal inhibitors of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1).
Article2018-06-13T19:35:16Z17β-estradiol (E2), the most potent estrogen in humans, known to be involved in the development and progession of estrogen-dependent diseases (EDD) like breast cancer and endometriosis. 17β-HSD1, which catalyses the reduction of the weak estrogen estrone (E1) to E2, is often overexpressed in breast cancer and endometriotic tissues. An inhibition of 17β-HSD1 could selectively reduce the local E2-level thus allowing for a novel, targeted approach in the treatment of EDD. Continuing our search for new nonsteroidal 17β-HSD1 inhibitors, a novel pharmacophore model was derived from crystallographic data and used for the virtual screening of a small library of compounds. Subsequent experimental verification of the virtual hits led to the identification of the moderately active compound 5. Rigidification and further structure modifications resulted in the discovery of a novel class of 17β-HSD1 inhibitors bearing a benzothiazole-scaffold linked to a phenyl ring via keto- or amide-bridge. Their putative binding modes were investigated by correlating their biological data with features of the pharmacophore model. The most active keto-derivative 6 shows IC₅₀-values in the nanomolar range for the transformation of E1 to E2 by 17β-HSD1, reasonable selectivity against 17β-HSD2 but pronounced affinity to the estrogen receptors (ERs). On the other hand, the best amide-derivative 21 shows only medium 17β-HSD1 inhibitory activity at the target enzyme as well as fair selectivity against 17β-HSD2 and ERs. The compounds 6 and 21 can be regarded as first benzothiazole-type 17β-HSD1 inhibitors for the development of potential therapeutics.oai:repository.helmholtz-hzi.de:10033/2667122019-08-30T11:30:32Zcom_10033_620656col_10033_620657
Bansal, Ranju
Thota, Sridhar
Karkra, Nalin
Minu, Maninder
Zimmer, Christina
Hartmann, Rolf W
University Institute of Pharmaceutical Sciences, Sector-14, Panjab University, Chandigarh 160 014, India. ranju29in@yahoo.co.in
2013-01-23T15:18:03Z
2013-01-23T15:18:03Z
2012-12
Synthesis and aromatase inhibitory activity of some new 16E-arylidenosteroids. 2012, 45:36-40 Bioorg. Chem.
1090-2120
23064126
10.1016/j.bioorg.2012.08.005
http://hdl.handle.net/10033/266712
Bioorganic chemistry
A new series of 16E-arylidene androstene derivatives has been synthesized and evaluated for aromatase inhibitory activity. The impact of various aryl substituents at 16 position of the steroid skeleton on aromatase inhibitory activity has been observed. The 16E-arylidenosteroids 6, 10 and 11 exhibited significant inhibition of the aromatase enzyme. 16-(4-Pyridylmethylene)-4-androstene-3,17-dione (6, IC(50): 5.2 μM) and 16-(benzo-[1,3]dioxol-5-ylmethylene)androsta-1,4-diene-3,17-dione (11, IC(50): 6.4 μM) were found to be approximately five times more potent in comparison to aminoglutethimide.
en
Archived with thanks to Bioorganic chemistry
Synthesis and aromatase inhibitory activity of some new 16E-arylidenosteroids.
Article2018-06-12T23:42:13ZA new series of 16E-arylidene androstene derivatives has been synthesized and evaluated for aromatase inhibitory activity. The impact of various aryl substituents at 16 position of the steroid skeleton on aromatase inhibitory activity has been observed. The 16E-arylidenosteroids 6, 10 and 11 exhibited significant inhibition of the aromatase enzyme. 16-(4-Pyridylmethylene)-4-androstene-3,17-dione (6, IC(50): 5.2 μM) and 16-(benzo-[1,3]dioxol-5-ylmethylene)androsta-1,4-diene-3,17-dione (11, IC(50): 6.4 μM) were found to be approximately five times more potent in comparison to aminoglutethimide.oai:repository.helmholtz-hzi.de:10033/2699122019-08-30T11:28:24Zcom_10033_620656col_10033_620657
Yin, Lina
Hu, Qingzhong
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University & Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarbrücken, Germany.
2013-02-21T08:04:32Z
2013-02-21T08:04:32Z
2012
3-Pyridyl substituted aliphatic cycles as CYP11B2 inhibitors: aromaticity abolishment of the core significantly increased selectivity over CYP1A2. 2012, 7 (11):e48048 PLoS ONE
1932-6203
23133610
10.1371/journal.pone.0048048
http://hdl.handle.net/10033/269912
PloS one
Aldosterone synthase (CYP11B2) is a promising therapeutic target for the treatment of cardiovascular diseases related to abnormally high aldosterone levels. On the basis of our previously identified lead compounds I-III, a series of 3-pyridinyl substituted aliphatic cycles were designed, synthesized and tested as CYP11B2 inhibitors. Aromaticity abolishment of the core was successfully applied to overcome the undesired CYP1A2 inhibition. This study resulted in a series of potent and selective CYP11B2 inhibitors, with compound 12 (IC(50) = 21 nM, SF = 50) as the most promising one, which shows no inhibition toward CYP1A2 at 2 µM. The design conception demonstrated in this study can be helpful in the optimization of CYP inhibitor drugs regarding CYP1A2 selectivity.
en
Archived with thanks to PloS one
3-Pyridyl substituted aliphatic cycles as CYP11B2 inhibitors: aromaticity abolishment of the core significantly increased selectivity over CYP1A2.
Article2018-06-12T17:49:31ZAldosterone synthase (CYP11B2) is a promising therapeutic target for the treatment of cardiovascular diseases related to abnormally high aldosterone levels. On the basis of our previously identified lead compounds I-III, a series of 3-pyridinyl substituted aliphatic cycles were designed, synthesized and tested as CYP11B2 inhibitors. Aromaticity abolishment of the core was successfully applied to overcome the undesired CYP1A2 inhibition. This study resulted in a series of potent and selective CYP11B2 inhibitors, with compound 12 (IC(50) = 21 nM, SF = 50) as the most promising one, which shows no inhibition toward CYP1A2 at 2 µM. The design conception demonstrated in this study can be helpful in the optimization of CYP inhibitor drugs regarding CYP1A2 selectivity.oai:repository.helmholtz-hzi.de:10033/2971952019-08-30T11:29:47Zcom_10033_620656col_10033_620657
Yin, Lina
Hu, Qingzhong
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University & Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C2-3, Saarbrücken D-66123, Germany. q.hu@mx.uni-saarland.de.
2013-08-01T09:32:52Z
2013-08-01T09:32:52Z
2013
Recent progress in pharmaceutical therapies for castration-resistant prostate cancer. 2013, 14 (7):13958-78 Int J Mol Sci
1422-0067
23880851
10.3390/ijms140713958
http://hdl.handle.net/10033/297195
International journal of molecular sciences
Since 2010, six drugs have been approved for the treatment of castration-resistant prostate cancer, i.e., CYP17 inhibitor Abiraterone, androgen receptor antagonist Enzalutamide, cytotoxic agent Cabazitaxel, vaccine Sipuleucel-T, antibody Denosumab against receptor activator of nuclear factor kappa B ligand and radiopharmaceutical Alpharadin. All these drugs demonstrate improvement on overall survival, expect for Denosumab, which increases the bone mineral density of patients under androgen deprivation therapy and prolongs bone-metastasis-free survival. Besides further CYP17 inhibitors (Orteronel, Galeterone, VT-464 and CFG920), androgen receptor antagonists (ARN-509, ODM-201, AZD-3514 and EZN-4176) and vaccine Prostvac, more drug candidates with various mechanisms or new indications of launched drugs are currently under evaluation in different stages of clinical trials, including various kinase inhibitors and platinum complexes. Some novel strategies have also been proposed aimed at further potentiation of antitumor effects or reduction of side effects and complications related to treatments. Under these flourishing circumstances, more investigations should be performed on the optimal combination or the sequence of treatments needed to delay or reverse possible resistance and thus maximize the clinical benefits for the patients.
en
Archived with thanks to International journal of molecular sciences
Recent progress in pharmaceutical therapies for castration-resistant prostate cancer.
Article2018-06-13T15:16:32ZSince 2010, six drugs have been approved for the treatment of castration-resistant prostate cancer, i.e., CYP17 inhibitor Abiraterone, androgen receptor antagonist Enzalutamide, cytotoxic agent Cabazitaxel, vaccine Sipuleucel-T, antibody Denosumab against receptor activator of nuclear factor kappa B ligand and radiopharmaceutical Alpharadin. All these drugs demonstrate improvement on overall survival, expect for Denosumab, which increases the bone mineral density of patients under androgen deprivation therapy and prolongs bone-metastasis-free survival. Besides further CYP17 inhibitors (Orteronel, Galeterone, VT-464 and CFG920), androgen receptor antagonists (ARN-509, ODM-201, AZD-3514 and EZN-4176) and vaccine Prostvac, more drug candidates with various mechanisms or new indications of launched drugs are currently under evaluation in different stages of clinical trials, including various kinase inhibitors and platinum complexes. Some novel strategies have also been proposed aimed at further potentiation of antitumor effects or reduction of side effects and complications related to treatments. Under these flourishing circumstances, more investigations should be performed on the optimal combination or the sequence of treatments needed to delay or reverse possible resistance and thus maximize the clinical benefits for the patients.oai:repository.helmholtz-hzi.de:10033/2982522019-08-30T11:28:51Zcom_10033_620656col_10033_620657
Krug, Sebastian J
Hu, Qingzhong
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University, Campus C2.3, 66123 Saarbrücken, Germany.
2013-08-14T14:20:01Z
2013-08-14T14:20:01Z
2013-03
Hits identified in library screening demonstrate selective CYP17A1 lyase inhibition. 2013, 134:75-9 J. Steroid Biochem. Mol. Biol.
1879-1220
23142656
10.1016/j.jsbmb.2012.10.019
http://hdl.handle.net/10033/298252
The Journal of steroid biochemistry and molecular biology
A screening of structurally different steroid hormone synthesis inhibitors was performed in order to find a starting point for the development of a new inhibitor of the bifunctional steroidogenic enzyme CYP17A1. Emphasis was placed on determination of selectivity between the two catalytic steps, namely 17α-hydroxylase and C(17,20)-lyase. For that purpose a new inhibition assay has been developed. Hits identified within this novel assay demonstrated selective inhibition of CYP17A1 lyase activity, and thus mark the basis for the development of selective C(17,20)-lyase inhibitors for the treatment of prostate cancer.
en
Archived with thanks to The Journal of steroid biochemistry and molecular biology
Enzyme Inhibitors
Humans
Inhibitory Concentration 50
Male
Prostatic Neoplasms
Small Molecule Libraries
Steroid 17-alpha-Hydroxylase
Hits identified in library screening demonstrate selective CYP17A1 lyase inhibition.
Article2018-06-12T23:39:19ZA screening of structurally different steroid hormone synthesis inhibitors was performed in order to find a starting point for the development of a new inhibitor of the bifunctional steroidogenic enzyme CYP17A1. Emphasis was placed on determination of selectivity between the two catalytic steps, namely 17α-hydroxylase and C(17,20)-lyase. For that purpose a new inhibition assay has been developed. Hits identified within this novel assay demonstrated selective inhibition of CYP17A1 lyase activity, and thus mark the basis for the development of selective C(17,20)-lyase inhibitors for the treatment of prostate cancer.oai:repository.helmholtz-hzi.de:10033/2983752019-08-30T11:26:42Zcom_10033_620656col_10033_620657
Berényi, Agnes
Frotscher, Martin
Marchais-Oberwinkler, Sandrine
Hartmann, Rolf W
Minorics, Renáta
Ocsovszki, Imre
Falkay, George
Zupkó, István
Department of Pharmacodynamics and Biopharmacy, University of Szeged , Szeged , Hungary.
2013-08-15T09:51:45Z
2013-08-15T09:51:45Z
2013-08
Direct antiproliferative effect of nonsteroidal 17β-hydroxysteroid dehydrogenase type 1 inhibitors in vitro. 2013, 28 (4):695-703 J Enzyme Inhib Med Chem
1475-6374
22471733
10.3109/14756366.2012.672414
http://hdl.handle.net/10033/298375
Journal of enzyme inhibition and medicinal chemistry
Inhibition of the local formation of estrogens seems to be an attractive strategy for pharmacological intervention in hormone-dependent disorders. The direct antiproliferative properties of ten nonsteroidal 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) inhibitors were investigated on human cancer cell lines of gynecological origin. The mechanism of the antiproliferative action was approximated by cell cycle analysis, fluorescent microscopy, BrdU assay, determination of caspase-3 activity and quantification of the expression of cell cycle regulators at mRNA level. Treatment of HeLa cells with some of the compounds resulted in a concentration-dependent inhibition of the G1-S transition and an increase in the apoptotic population. The most effective agents increased the expression of tumor suppressors p21 and p53, while CDK2 and Rb were down-regulated. The reported anticancer actions of the tested compounds are independent of the 17β-HSD1-inhibiting capacity. These results indicate that it is possible to combine direct antiproliferative activity and 17β-HSD1 inhibition resulting in novel agents with dual mode of action.
en
Archived with thanks to Journal of enzyme inhibition and medicinal chemistry
Direct antiproliferative effect of nonsteroidal 17β-hydroxysteroid dehydrogenase type 1 inhibitors in vitro.
Article2014-08-15T00:00:00ZInhibition of the local formation of estrogens seems to be an attractive strategy for pharmacological intervention in hormone-dependent disorders. The direct antiproliferative properties of ten nonsteroidal 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) inhibitors were investigated on human cancer cell lines of gynecological origin. The mechanism of the antiproliferative action was approximated by cell cycle analysis, fluorescent microscopy, BrdU assay, determination of caspase-3 activity and quantification of the expression of cell cycle regulators at mRNA level. Treatment of HeLa cells with some of the compounds resulted in a concentration-dependent inhibition of the G1-S transition and an increase in the apoptotic population. The most effective agents increased the expression of tumor suppressors p21 and p53, while CDK2 and Rb were down-regulated. The reported anticancer actions of the tested compounds are independent of the 17β-HSD1-inhibiting capacity. These results indicate that it is possible to combine direct antiproliferative activity and 17β-HSD1 inhibition resulting in novel agents with dual mode of action.oai:repository.helmholtz-hzi.de:10033/2992512019-08-30T11:26:06Zcom_10033_620656col_10033_620657
Hamed, Mostafa M.
Abou El Ella, Dalal A.
Keeton, Adam B.
Piazza, Gary A.
Engel, Matthias
Hartmann, Rolf W.
Abadi, Ashraf H.
2013-08-20T12:39:00Z
2013-08-20T12:39:00Z
2013-08-20
Quinazoline and tetrahydropyridothieno[2,3-d]pyrimidine derivatives as irreversible EGFR tyrosine kinase inhibitors: influence of the position 4 substituent 2013, 4 (8):1202 MedChemComm
2040-2503
2040-2511
10.1039/c3md00118k
http://hdl.handle.net/10033/299251
MedChemComm
http://xlink.rsc.org/?DOI=c3md00118k
Archived with thanks to MedChemComm
Quinazoline and tetrahydropyridothieno[2,3-d]pyrimidine derivatives as irreversible EGFR tyrosine kinase inhibitors: influence of the position 4 substituent
Article2018-06-12T17:30:28Zoai:repository.helmholtz-hzi.de:10033/2995042019-08-30T11:32:16Zcom_10033_620656col_10033_620657
Perspicace, Enrico
Marchais-Oberwinkler, Sandrine
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University, Campus C23, D-66123 Saarbrücken, Germany.
2013-08-22T12:14:57Z
2013-08-22T12:14:57Z
2013
Synthesis and biological evaluation of thieno[3,2-d]- pyrimidinones, thieno[3,2-d]pyrimidines and quinazolinones: conformationally restricted 17b-hydroxysteroid dehydrogenase type 2 (17b-HSD2) inhibitors. 2013, 18 (4):4487-509 Molecules
1420-3049
23591928
10.3390/molecules18044487
http://hdl.handle.net/10033/299504
Molecules (Basel, Switzerland)
In this study, a series of conformationally restricted thieno[3,2-d]pyrimidinones, thieno[3,2-d]pyrimidines and quinazolinones was designed and synthesized with the goal of improving the biological activity as 17b-hydroxysteroid dehydrogenase type 2 inhibitors of the corresponding amidothiophene derivatives. Two moderately active compounds were discovered and this allowed the identification of the biologically active open conformer as well as the extension of the enzyme binding site characterisation.
en
Archived with thanks to Molecules (Basel, Switzerland)
Synthesis and biological evaluation of thieno[3,2-d]- pyrimidinones, thieno[3,2-d]pyrimidines and quinazolinones: conformationally restricted 17b-hydroxysteroid dehydrogenase type 2 (17b-HSD2) inhibitors.
Article2018-06-13T03:44:10ZIn this study, a series of conformationally restricted thieno[3,2-d]pyrimidinones, thieno[3,2-d]pyrimidines and quinazolinones was designed and synthesized with the goal of improving the biological activity as 17b-hydroxysteroid dehydrogenase type 2 inhibitors of the corresponding amidothiophene derivatives. Two moderately active compounds were discovered and this allowed the identification of the biologically active open conformer as well as the extension of the enzyme binding site characterisation.oai:repository.helmholtz-hzi.de:10033/3037382019-08-30T11:28:51Zcom_10033_620656col_10033_620657
Köberle, Verena
Pleli, Thomas
Schmithals, Christian
Augusto Alonso, Eduardo
Haupenthal, Jörg
Bönig, Halvard
Peveling-Oberhag, Jan
Biondi, Ricardo M
Zeuzem, Stefan
Kronenberger, Bernd
Waidmann, Oliver
Piiper, Albrecht
Department of Medicine I, University Hospital Frankfurt, Frankfurt, Germany.
2013-10-21T14:39:02Z
2013-10-21T14:39:02Z
2013
Differential Stability of Cell-Free Circulating microRNAs: Implications for Their Utilization as Biomarkers. 2013, 8 (9):e75184 PLoS ONE
1932-6203
24073250
10.1371/journal.pone.0075184
http://hdl.handle.net/10033/303738
PloS one
MicroRNAs circulating in the blood, stabilized by complexation with proteins and/or additionally by encapsulation in lipid vesicles, are currently being evaluated as biomarkers. The consequences of their differential association with lipids/vesicles for their stability and use as biomarkers are largely unexplored and are subject of the present study.
en
Archived with thanks to PloS one
Differential Stability of Cell-Free Circulating microRNAs: Implications for Their Utilization as Biomarkers.
Article2018-06-12T23:04:31ZMicroRNAs circulating in the blood, stabilized by complexation with proteins and/or additionally by encapsulation in lipid vesicles, are currently being evaluated as biomarkers. The consequences of their differential association with lipids/vesicles for their stability and use as biomarkers are largely unexplored and are subject of the present study.oai:repository.helmholtz-hzi.de:10033/3063732019-08-30T11:33:57Zcom_10033_620656col_10033_620657
Maurer, Christine K
Steinbach, Anke
Hartmann, Rolf W
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Campus C2.3, D-66123 Saarbrücken, Germany. Electronic address: christine.maurer@helmholtz-hzi.de.
2013-12-05T12:46:06Z
2013-12-05T12:46:06Z
2013-12
Development and validation of a UHPLC-MS/MS procedure for quantification of the Pseudomonas Quinolone Signal in bacterial culture after acetylation for characterization of new quorum sensing inhibitors. 2013, 86:127-34 J Pharm Biomed Anal
1873-264X
24001903
10.1016/j.jpba.2013.07.047
http://hdl.handle.net/10033/306373
Journal of pharmaceutical and biomedical analysis
The appearance of antibiotic resistance requires novel therapeutic strategies. One approach is to selectively attenuate bacterial pathogenicity by interfering with bacterial cell-to-cell communication known as quorum sensing. The PQS quorum sensing system of Pseudomonas aeruginosa employs as signal molecule the Pseudomonas Quinolone Signal (PQS; 2-heptyl-3-hydroxy-4-(1H)-quinolone), a key contributor to virulence and biofilm formation. Thus, interference with PQS production is considered as promising approach for the development of novel anti-infectives. Therefore, in this study, we developed and validated an ultra-high performance liquid chromatographic-tandem mass spectrometric approach for reliable quantification of PQS in P. aeruginosa cultures for activity determination of new quorum sensing inhibitors. The poor chromatographic properties of PQS reported by others could be overcome by fast microwave-assisted acetylation. The validation procedure including matrix effects, recovery, process efficiency, selectivity, carry-over, accuracy and precision, stability of the processed sample, and limit of quantification demonstrated that the method fulfilled all requirements of common validation guidelines. Its applicability was successfully proven in routine testing. In addition, two-point calibration was shown to be applicable for fast and reliable PQS quantification saving time and resources. In summary, the described method provides a powerful tool for the discovery of new quorum sensing inhibitors as potential anti-infectives and illustrated the usefulness of chemical derivatization, acetylation, in liquid chromatography-mass spectrometry analysis.
en
Archived with thanks to Journal of pharmaceutical and biomedical analysis
Development and validation of a UHPLC-MS/MS procedure for quantification of the Pseudomonas Quinolone Signal in bacterial culture after acetylation for characterization of new quorum sensing inhibitors.
Article2018-06-12T22:42:29ZThe appearance of antibiotic resistance requires novel therapeutic strategies. One approach is to selectively attenuate bacterial pathogenicity by interfering with bacterial cell-to-cell communication known as quorum sensing. The PQS quorum sensing system of Pseudomonas aeruginosa employs as signal molecule the Pseudomonas Quinolone Signal (PQS; 2-heptyl-3-hydroxy-4-(1H)-quinolone), a key contributor to virulence and biofilm formation. Thus, interference with PQS production is considered as promising approach for the development of novel anti-infectives. Therefore, in this study, we developed and validated an ultra-high performance liquid chromatographic-tandem mass spectrometric approach for reliable quantification of PQS in P. aeruginosa cultures for activity determination of new quorum sensing inhibitors. The poor chromatographic properties of PQS reported by others could be overcome by fast microwave-assisted acetylation. The validation procedure including matrix effects, recovery, process efficiency, selectivity, carry-over, accuracy and precision, stability of the processed sample, and limit of quantification demonstrated that the method fulfilled all requirements of common validation guidelines. Its applicability was successfully proven in routine testing. In addition, two-point calibration was shown to be applicable for fast and reliable PQS quantification saving time and resources. In summary, the described method provides a powerful tool for the discovery of new quorum sensing inhibitors as potential anti-infectives and illustrated the usefulness of chemical derivatization, acetylation, in liquid chromatography-mass spectrometry analysis.oai:repository.helmholtz-hzi.de:10033/3114212019-08-30T11:26:42Zcom_10033_620656col_10033_620657
Steinbach, Anke
Maurer, Christine K
Weidel, Elisabeth
Henn, Claudia
Brengel, Christian
Hartmann, Rolf W
Negri, Matthias
2014-01-16T14:53:04Z
2014-01-16T14:53:04Z
2013
Molecular basis of HHQ biosynthesis: molecular dynamics simulations, enzyme kinetic and surface plasmon resonance studies. 2013, 6 (1):10 BMC Biophys
2046-1682
23916145
10.1186/2046-1682-6-10
http://hdl.handle.net/10033/311421
BMC biophysics
PQS (PseudomonasQuinolone Signal) and its precursor HHQ are signal molecules of the P. aeruginosa quorum sensing system. They explicate their role in mammalian pathogenicity by binding to the receptor PqsR that induces virulence factor production and biofilm formation. The enzyme PqsD catalyses the biosynthesis of HHQ.
en
Archived with thanks to BMC biophysics
Molecular basis of HHQ biosynthesis: molecular dynamics simulations, enzyme kinetic and surface plasmon resonance studies.
Article2018-06-12T23:48:53ZPQS (PseudomonasQuinolone Signal) and its precursor HHQ are signal molecules of the P. aeruginosa quorum sensing system. They explicate their role in mammalian pathogenicity by binding to the receptor PqsR that induces virulence factor production and biofilm formation. The enzyme PqsD catalyses the biosynthesis of HHQ.oai:repository.helmholtz-hzi.de:10033/3116762019-08-30T11:26:42Zcom_10033_620656col_10033_620657
Elgaher, Walid A. M.
Fruth, Martina
Groh, Matthias
Haupenthal, Jörg
Hartmann, Rolf W.
Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C2.3, Saarland University, 66123 Saarbrücken, Germany
2014-01-22T14:47:34Z
2014-01-22T14:47:34Z
2014-01-22
Expanding the scaffold for bacterial RNA polymerase inhibitors: design, synthesis and structure–activity relationships of ureido-heterocyclic-carboxylic acids 2014, 4 (5):2177 RSC Advances
2046-2069
10.1039/c3ra45820b
http://hdl.handle.net/10033/311676
RSC Advances
http://xlink.rsc.org/?DOI=c3ra45820b
Archived with thanks to RSC Advances
Expanding the scaffold for bacterial RNA polymerase inhibitors: design, synthesis and structure–activity relationships of ureido-heterocyclic-carboxylic acids
Article2014-10-24T00:00:00Zoai:repository.helmholtz-hzi.de:10033/3119292019-08-30T11:33:01Zcom_10033_620656col_10033_620657
Grombein, Cornelia M.
Hu, Qingzhong
Heim, Ralf
Huch, Volker
Hartmann, Rolf W.
Helmholtz-Institut für Pharmazeutische Forschung Saarland
2014-01-27T13:53:31Z
2014-01-27T13:53:31Z
2014-01-27
Unexpected results of a SNAr-reaction. A novel synthetic approach to 1-arylthio-2-naphthols 2013, 54 (48):6615 Tetrahedron Letters
404039
10.1016/j.tetlet.2013.09.111
http://hdl.handle.net/10033/311929
Tetrahedron Letters
http://linkinghub.elsevier.com/retrieve/pii/S0040403913016766
Archived with thanks to Tetrahedron Letters
Unexpected results of a SNAr-reaction. A novel synthetic approach to 1-arylthio-2-naphthols
Article2018-06-12T22:30:42Zoai:repository.helmholtz-hzi.de:10033/3167182019-08-30T11:33:57Zcom_10033_620656col_10033_620657
Lu, Cenbin
Maurer, Christine K
Kirsch, Benjamin
Steinbach, Anke
Hartmann, Rolf W
Division of Drug design and optimization. Helmholtz-Institute for Pharmaceutical Research Saarland & Pharmaceutical and Medicinal Chemistry, Saarland University.
2014-05-12T09:42:12Z
2014-05-12T09:42:12Z
2014-01-20
Overcoming the unexpected functional inversion of a PqsR antagonist in Pseudomonas aeruginosa: an in vivo potent antivirulence agent targeting pqs quorum sensing. 2014, 53 (4):1109-12 Angew. Chem. Int. Ed. Engl.
1521-3773
24338917
10.1002/anie.201307547
http://hdl.handle.net/10033/316718
Angewandte Chemie (International ed. in English)
The virulence regulator PqsR of Pseudomonas aeruginosa is considered as an attractive target for attenuating the bacterial pathogenicity without eliciting resistance. However, despite efforts and desires, no promising PqsR antagonist has been discovered thus far. Now, a surprising functionality change of a highly affine PqsR antagonist in P. aeruginosa is revealed, which is mediated by a bacterial signal molecule synthase and responsible for low cellular potency. Blockade of the susceptible position led to the discovery of the first antivirulence compound that is potent in vivo and targets PqsR, thus providing a proof of concept for this novel antivirulence therapy.
en
Archived with thanks to Angewandte Chemie (International ed. in English)
Overcoming the unexpected functional inversion of a PqsR antagonist in Pseudomonas aeruginosa: an in vivo potent antivirulence agent targeting pqs quorum sensing.
Article2015-01-15T00:00:00ZThe virulence regulator PqsR of Pseudomonas aeruginosa is considered as an attractive target for attenuating the bacterial pathogenicity without eliciting resistance. However, despite efforts and desires, no promising PqsR antagonist has been discovered thus far. Now, a surprising functionality change of a highly affine PqsR antagonist in P. aeruginosa is revealed, which is mediated by a bacterial signal molecule synthase and responsible for low cellular potency. Blockade of the susceptible position led to the discovery of the first antivirulence compound that is potent in vivo and targets PqsR, thus providing a proof of concept for this novel antivirulence therapy.oai:repository.helmholtz-hzi.de:10033/3227012019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Hinsberger, Stefan
de Jong, Johannes C
Groh, Matthias
Haupenthal, Jörg
Hartmann, Rolf W
2014-07-09T14:37:21Z
2014-07-09T14:37:21Z
2014-04-09
Benzamidobenzoic acids as potent PqsD inhibitors for the treatment of Pseudomonas aeruginosa infections. 2014, 76:343-51 Eur J Med Chem
1768-3254
24589489
10.1016/j.ejmech.2014.02.014
http://hdl.handle.net/10033/322701
European journal of medicinal chemistry
Targeting PqsD is a promising novel approach to disrupt bacterial cell-to-cell-communication in Pseudomonas aeruginosa. In search of selective PqsD inhibitors, two series of benzamidobenzoic acids - one published as RNAP inhibitors and the other as PqsD inhibitors - were investigated for inhibitory activity toward the respective other enzyme. Additionally, novel derivatives were synthesized and biologically evaluated. By this means, the structural features needed for benzamidobenzoic acids to be potent and, most notably, selective PqsD inhibitors were identified. The most interesting compound of this study was the 3-Cl substituted compound 5 which strongly inhibits PqsD (IC₅₀ 6.2 μM) while exhibiting no inhibition of RNAP.
en
Archived with thanks to European journal of medicinal chemistry
Benzamidobenzoic acids as potent PqsD inhibitors for the treatment of Pseudomonas aeruginosa infections.
Article2018-06-12T20:01:54ZTargeting PqsD is a promising novel approach to disrupt bacterial cell-to-cell-communication in Pseudomonas aeruginosa. In search of selective PqsD inhibitors, two series of benzamidobenzoic acids - one published as RNAP inhibitors and the other as PqsD inhibitors - were investigated for inhibitory activity toward the respective other enzyme. Additionally, novel derivatives were synthesized and biologically evaluated. By this means, the structural features needed for benzamidobenzoic acids to be potent and, most notably, selective PqsD inhibitors were identified. The most interesting compound of this study was the 3-Cl substituted compound 5 which strongly inhibits PqsD (IC₅₀ 6.2 μM) while exhibiting no inhibition of RNAP.oai:repository.helmholtz-hzi.de:10033/3249672019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Abdelsamie, Ahmed S
Bey, Emmanuel
Hanke, Nina
Empting, Martin
Hartmann, Rolf W
Frotscher, Martin
2014-08-19T09:52:53Z
2014-08-19T09:52:53Z
2014-07-23
Inhibition of 17β-HSD1: SAR of bicyclic substituted hydroxyphenylmethanones and discovery of new potent inhibitors with thioether linker. 2014, 82:394-406 Eur J Med Chem
1768-3254
24929290
10.1016/j.ejmech.2014.05.074
http://hdl.handle.net/10033/324967
European journal of medicinal chemistry
Estradiol is the most potent estrogen in humans. It is known to be involved in the development and proliferation of estrogen dependent diseases such as breast cancer and endometriosis. The last step of its biosynthesis is catalyzed by 17β-hydroxysteroid dehydrogenase type 1 (17β- HSD1) which consequently is a promising target for the treatment of these diseases. Recently, we reported on bicyclic substituted hydroxyphenylmethanones as potent inhibitors of 17β-HSD1. The present study focuses on rational structural modifications in this compound class with the aim of gaining more insight into its structure-activity relationship (SAR). (4-Hydroxyphenyl)-(5-(3-hydroxyphenylsulfanyl)-thiophen-2-yl)methanone (25) was discovered as a member of a novel potent class of human 17β-HSD1 inhibitors. Computational methods were used to elucidate its interactions with the target protein. The compound showed activity also towards the murine 17β-HSD1 enzyme and thus is a starting point for the design of compounds suitable for evaluation in an animal disease model.
en
Archived with thanks to European journal of medicinal chemistry
Inhibition of 17β-HSD1: SAR of bicyclic substituted hydroxyphenylmethanones and discovery of new potent inhibitors with thioether linker.
Article2018-06-13T09:09:56ZEstradiol is the most potent estrogen in humans. It is known to be involved in the development and proliferation of estrogen dependent diseases such as breast cancer and endometriosis. The last step of its biosynthesis is catalyzed by 17β-hydroxysteroid dehydrogenase type 1 (17β- HSD1) which consequently is a promising target for the treatment of these diseases. Recently, we reported on bicyclic substituted hydroxyphenylmethanones as potent inhibitors of 17β-HSD1. The present study focuses on rational structural modifications in this compound class with the aim of gaining more insight into its structure-activity relationship (SAR). (4-Hydroxyphenyl)-(5-(3-hydroxyphenylsulfanyl)-thiophen-2-yl)methanone (25) was discovered as a member of a novel potent class of human 17β-HSD1 inhibitors. Computational methods were used to elucidate its interactions with the target protein. The compound showed activity also towards the murine 17β-HSD1 enzyme and thus is a starting point for the design of compounds suitable for evaluation in an animal disease model.oai:repository.helmholtz-hzi.de:10033/3250052019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Lu, Cenbin
Kirsch, Benjamin
Maurer, Christine K
de Jong, Johannes C
Braunshausen, Andrea
Steinbach, Anke
Hartmann, Rolf W
Helmholtz-Institut für Pharmazeutische Forschung Saarland Campus, Geb. C2.3 Universität des Saarlandes, D-66123 Saarbrücken, Germany.
2014-08-20T09:16:05Z
2014-08-20T09:16:05Z
2014-05-22
Optimization of anti-virulence PqsR antagonists regarding aqueous solubility and biological properties resulting in new insights in structure-activity relationships. 2014, 79:173-83 Eur J Med Chem
1768-3254
24735643
10.1016/j.ejmech.2014.04.016
http://hdl.handle.net/10033/325005
European journal of medicinal chemistry
Increasing antibiotic resistance urgently requires novel therapeutic options to combat bacterial infections. The anti-virulence therapy selectively intervening with pathogenicity without affecting bacterial viability is such a strategy to overcome resistance. We consider the virulence regulator PqsR as an attractive target in the human pathogen Pseudomonas aeruginosa, and recently discovered the first PqsR antagonists, which, however, suffered from poor aqueous solubility. In this work, the antagonists were structurally modified to become more soluble, and their structure-activity as well as structure-property relationships were studied. A novel promising compound with improved solubility and enhanced anti-virulence activity was discovered (IC50: 3.8 μM, pyocyanin). Our findings emphasize the crucial role of substituents at the 3-position and the carbonyl group at the 4-position for ligand-receptor interactions, and illuminate the way for further optimization of PqsR antagonists as anti-virulence agents.
en
Archived with thanks to European journal of medicinal chemistry
Optimization of anti-virulence PqsR antagonists regarding aqueous solubility and biological properties resulting in new insights in structure-activity relationships.
Article2018-06-13T01:37:35ZIncreasing antibiotic resistance urgently requires novel therapeutic options to combat bacterial infections. The anti-virulence therapy selectively intervening with pathogenicity without affecting bacterial viability is such a strategy to overcome resistance. We consider the virulence regulator PqsR as an attractive target in the human pathogen Pseudomonas aeruginosa, and recently discovered the first PqsR antagonists, which, however, suffered from poor aqueous solubility. In this work, the antagonists were structurally modified to become more soluble, and their structure-activity as well as structure-property relationships were studied. A novel promising compound with improved solubility and enhanced anti-virulence activity was discovered (IC50: 3.8 μM, pyocyanin). Our findings emphasize the crucial role of substituents at the 3-position and the carbonyl group at the 4-position for ligand-receptor interactions, and illuminate the way for further optimization of PqsR antagonists as anti-virulence agents.oai:repository.helmholtz-hzi.de:10033/3260692019-08-30T11:36:32Zcom_10033_620656col_10033_620658
Wohlschlager, Therese
Butschi, Alex
Grassi, Paola
Sutov, Grigorij
Gauss, Robert
Hauck, Dirk
Schmieder, Stefanie S
Knobel, Martin
Titz, Alexander
Dell, Anne
Haslam, Stuart M
Hengartner, Michael O
Aebi, Markus
Künzler, Markus
2014-09-12T09:43:18Z
2014-09-12T09:43:18Z
2014-07-08
Methylated glycans as conserved targets of animal and fungal innate defense. 2014, 111 (27):E2787-96 Proc. Natl. Acad. Sci. U.S.A.
1091-6490
24879441
10.1073/pnas.1401176111
http://hdl.handle.net/10033/326069
Proceedings of the National Academy of Sciences of the United States of America
Effector proteins of innate immune systems recognize specific non-self epitopes. Tectonins are a family of β-propeller lectins conserved from bacteria to mammals that have been shown to bind bacterial lipopolysaccharide (LPS). We present experimental evidence that two Tectonins of fungal and animal origin have a specificity for O-methylated glycans. We show that Tectonin 2 of the mushroom Laccaria bicolor (Lb-Tec2) agglutinates Gram-negative bacteria and exerts toxicity toward the model nematode Caenorhabditis elegans, suggesting a role in fungal defense against bacteria and nematodes. Biochemical and genetic analysis of these interactions revealed that both bacterial agglutination and nematotoxicity of Lb-Tec2 depend on the recognition of methylated glycans, namely O-methylated mannose and fucose residues, as part of bacterial LPS and nematode cell-surface glycans. In addition, a C. elegans gene, termed samt-1, coding for a candidate membrane transport protein for the presumptive donor substrate of glycan methylation, S-adenosyl-methionine, from the cytoplasm to the Golgi was identified. Intriguingly, limulus lectin L6, a structurally related antibacterial protein of the Japanese horseshoe crab Tachypleus tridentatus, showed properties identical to the mushroom lectin. These results suggest that O-methylated glycans constitute a conserved target of the fungal and animal innate immune system. The broad phylogenetic distribution of O-methylated glycans increases the spectrum of potential antagonists recognized by Tectonins, rendering this conserved protein family a universal defense armor.
en
Archived with thanks to Proceedings of the National Academy of Sciences of the United States of America
Methylated glycans as conserved targets of animal and fungal innate defense.
Article2018-06-13T04:02:01ZEffector proteins of innate immune systems recognize specific non-self epitopes. Tectonins are a family of β-propeller lectins conserved from bacteria to mammals that have been shown to bind bacterial lipopolysaccharide (LPS). We present experimental evidence that two Tectonins of fungal and animal origin have a specificity for O-methylated glycans. We show that Tectonin 2 of the mushroom Laccaria bicolor (Lb-Tec2) agglutinates Gram-negative bacteria and exerts toxicity toward the model nematode Caenorhabditis elegans, suggesting a role in fungal defense against bacteria and nematodes. Biochemical and genetic analysis of these interactions revealed that both bacterial agglutination and nematotoxicity of Lb-Tec2 depend on the recognition of methylated glycans, namely O-methylated mannose and fucose residues, as part of bacterial LPS and nematode cell-surface glycans. In addition, a C. elegans gene, termed samt-1, coding for a candidate membrane transport protein for the presumptive donor substrate of glycan methylation, S-adenosyl-methionine, from the cytoplasm to the Golgi was identified. Intriguingly, limulus lectin L6, a structurally related antibacterial protein of the Japanese horseshoe crab Tachypleus tridentatus, showed properties identical to the mushroom lectin. These results suggest that O-methylated glycans constitute a conserved target of the fungal and animal innate immune system. The broad phylogenetic distribution of O-methylated glycans increases the spectrum of potential antagonists recognized by Tectonins, rendering this conserved protein family a universal defense armor.oai:repository.helmholtz-hzi.de:10033/3261742019-08-30T11:27:16Zcom_10033_620656col_10033_620657
Zhu, Weixing
Haupenthal, Jörg
Groh, Matthias
Fountain, Michelle
Hartmann, Rolf W
2014-09-16T12:41:07Z
2014-09-16T12:41:07Z
2014-07
New insights into the bacterial RNA polymerase inhibitor CBR703 as a starting point for optimization as an anti-infective agent. 2014, 58 (7):4242-5 Antimicrob. Agents Chemother.
1098-6596
24820077
10.1128/AAC.02600-14
http://hdl.handle.net/10033/326174
Antimicrobial agents and chemotherapy
CBR703 was reported to inhibit bacterial RNA polymerase (RNAP) and biofilm formation, considering it to be a good candidate for further optimization. While synthesized derivatives of CBR703 did not result in more-active RNAP inhibitors, we observed promising antibacterial activities. These again correlated with a significant cytotoxicity toward mammalian cells. Furthermore, we suspect the promising effects on biofilm formation to be artifacts. Consequently, this class of compounds can be considered unattractive as antibacterial agents.
en
Archived with thanks to Antimicrobial agents and chemotherapy
New insights into the bacterial RNA polymerase inhibitor CBR703 as a starting point for optimization as an anti-infective agent.
Article2018-06-12T22:50:31ZCBR703 was reported to inhibit bacterial RNA polymerase (RNAP) and biofilm formation, considering it to be a good candidate for further optimization. While synthesized derivatives of CBR703 did not result in more-active RNAP inhibitors, we observed promising antibacterial activities. These again correlated with a significant cytotoxicity toward mammalian cells. Furthermore, we suspect the promising effects on biofilm formation to be artifacts. Consequently, this class of compounds can be considered unattractive as antibacterial agents.oai:repository.helmholtz-hzi.de:10033/3365532019-08-30T11:36:05Zcom_10033_620656col_10033_620658
Butschi, Alex
Titz, Alexander
Wälti, Martin A
Olieric, Vincent
Paschinger, Katharina
Nöbauer, Katharina
Guo, Xiaoqiang
Seeberger, Peter H
Wilson, Iain B H
Aebi, Markus
Hengartner, Michael O
Künzler, Markus
Institute of Molecular Biology, University of Zürich, Zürich, Switzerland.
2014-12-03T10:32:51Z
2014-12-03T10:32:51Z
2010-01
Caenorhabditis elegans N-glycan core beta-galactoside confers sensitivity towards nematotoxic fungal galectin CGL2. 2010, 6 (1):e1000717 PLoS Pathog.
1553-7374
20062796
10.1371/journal.ppat.1000717
http://hdl.handle.net/10033/336553
PLoS pathogens
The physiological role of fungal galectins has remained elusive. Here, we show that feeding of a mushroom galectin, Coprinopsis cinerea CGL2, to Caenorhabditis elegans inhibited development and reproduction and ultimately resulted in killing of this nematode. The lack of toxicity of a carbohydrate-binding defective CGL2 variant and the resistance of a C. elegans mutant defective in GDP-fucose biosynthesis suggested that CGL2-mediated nematotoxicity depends on the interaction between the galectin and a fucose-containing glycoconjugate. A screen for CGL2-resistant worm mutants identified this glycoconjugate as a Galbeta1,4Fucalpha1,6 modification of C. elegans N-glycan cores. Analysis of N-glycan structures in wild type and CGL2-resistant nematodes confirmed this finding and allowed the identification of a novel putative glycosyltransferase required for the biosynthesis of this glycoepitope. The X-ray crystal structure of a complex between CGL2 and the Galbeta1,4Fucalpha1,6GlcNAc trisaccharide at 1.5 A resolution revealed the biophysical basis for this interaction. Our results suggest that fungal galectins play a role in the defense of fungi against predators by binding to specific glycoconjugates of these organisms.
en
Agaricales
Amino Acid Sequence
Animals
Caenorhabditis elegans
Caenorhabditis elegans Proteins
Fungal Proteins
Galactosides
Galectin 2
Molecular Sequence Data
Nematode Infections
Protein Structure, Quaternary
Structure-Activity Relationship
Caenorhabditis elegans N-glycan core beta-galactoside confers sensitivity towards nematotoxic fungal galectin CGL2.
Article2018-06-13T03:47:23ZThe physiological role of fungal galectins has remained elusive. Here, we show that feeding of a mushroom galectin, Coprinopsis cinerea CGL2, to Caenorhabditis elegans inhibited development and reproduction and ultimately resulted in killing of this nematode. The lack of toxicity of a carbohydrate-binding defective CGL2 variant and the resistance of a C. elegans mutant defective in GDP-fucose biosynthesis suggested that CGL2-mediated nematotoxicity depends on the interaction between the galectin and a fucose-containing glycoconjugate. A screen for CGL2-resistant worm mutants identified this glycoconjugate as a Galbeta1,4Fucalpha1,6 modification of C. elegans N-glycan cores. Analysis of N-glycan structures in wild type and CGL2-resistant nematodes confirmed this finding and allowed the identification of a novel putative glycosyltransferase required for the biosynthesis of this glycoepitope. The X-ray crystal structure of a complex between CGL2 and the Galbeta1,4Fucalpha1,6GlcNAc trisaccharide at 1.5 A resolution revealed the biophysical basis for this interaction. Our results suggest that fungal galectins play a role in the defense of fungi against predators by binding to specific glycoconjugates of these organisms.oai:repository.helmholtz-hzi.de:10033/3365872019-08-30T11:36:32Zcom_10033_620656col_10033_620658
Sommer, Roman
Exner, Thomas E
Titz, Alexander
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C 2.3, D-66123, Saarbrücken, Germany; Department of Chemistry and Graduate School Chemical Biology, University of Konstanz, D-78457, Konstanz, Germany.
2014-12-04T10:46:13Z
2014-12-04T10:46:13Z
2014
A Biophysical Study with Carbohydrate Derivatives Explains the Molecular Basis of Monosaccharide Selectivity of the Pseudomonas aeruginosa Lectin LecB. 2014, 9 (11):e112822 PLoS ONE
1932-6203
25415418
10.1371/journal.pone.0112822
http://hdl.handle.net/10033/336587
PloS one
The rise of resistances against antibiotics in bacteria is a major threat for public health and demands the development of novel antibacterial therapies. Infections with Pseudomonas aeruginosa are a severe problem for hospitalized patients and for patients suffering from cystic fibrosis. These bacteria can form biofilms and thereby increase their resistance towards antibiotics. The bacterial lectin LecB was shown to be necessary for biofilm formation and the inhibition with its carbohydrate ligands resulted in reduced amounts of biofilm. The natural ligands for LecB are glycosides of d-mannose and l-fucose, the latter displaying an unusual strong affinity. Interestingly, although mannosides are much weaker ligands for LecB, they do form an additional hydrogen bond with the protein in the crystal structure. To analyze the individual contributions of the methyl group in fucosides and the hydroxymethyl group in mannosides to the binding, we designed and synthesized derivatives of these saccharides. We report glycomimetic inhibitors that dissect the individual interactions of their saccharide precursors with LecB and give insight into the biophysics of binding by LecB. Furthermore, theoretical calculations supported by experimental thermodynamic data suggest a perturbed hydrogen bonding network for mannose derivatives as molecular basis for the selectivity of LecB for fucosides. Knowledge gained on the mode of interaction of LecB with its ligands at ambient conditions will be useful for future drug design.
en
A Biophysical Study with Carbohydrate Derivatives Explains the Molecular Basis of Monosaccharide Selectivity of the Pseudomonas aeruginosa Lectin LecB.
Article2018-06-13T20:04:59ZThe rise of resistances against antibiotics in bacteria is a major threat for public health and demands the development of novel antibacterial therapies. Infections with Pseudomonas aeruginosa are a severe problem for hospitalized patients and for patients suffering from cystic fibrosis. These bacteria can form biofilms and thereby increase their resistance towards antibiotics. The bacterial lectin LecB was shown to be necessary for biofilm formation and the inhibition with its carbohydrate ligands resulted in reduced amounts of biofilm. The natural ligands for LecB are glycosides of d-mannose and l-fucose, the latter displaying an unusual strong affinity. Interestingly, although mannosides are much weaker ligands for LecB, they do form an additional hydrogen bond with the protein in the crystal structure. To analyze the individual contributions of the methyl group in fucosides and the hydroxymethyl group in mannosides to the binding, we designed and synthesized derivatives of these saccharides. We report glycomimetic inhibitors that dissect the individual interactions of their saccharide precursors with LecB and give insight into the biophysics of binding by LecB. Furthermore, theoretical calculations supported by experimental thermodynamic data suggest a perturbed hydrogen bonding network for mannose derivatives as molecular basis for the selectivity of LecB for fucosides. Knowledge gained on the mode of interaction of LecB with its ligands at ambient conditions will be useful for future drug design.oai:repository.helmholtz-hzi.de:10033/3367002019-08-30T11:36:32Zcom_10033_620656col_10033_620658
Sommer, Roman
Joachim, Ines
Wagner, Stefanie
Titz, Alexander
University of Konstanz, Department of Chemistry and Zukunftskolleg, Universitätsstrasse 10, D-78457 Konstanz.
2014-12-05T09:59:07Z
2014-12-05T09:59:07Z
2013
New approaches to control infections: anti-biofilm strategies against gram-negative bacteria. 2013, 67 (4):286-90 Chimia (Aarau)
0009-4293
23967708
http://hdl.handle.net/10033/336700
Chimia
Hospital-acquired bacterial infections, especially with Gram-negative pathogens, present a major threat due to the rapid spread of antibiotic-resistant strains. Targeting mechanisms of bacterial virulence has recently appeared as a promising new therapeutic paradigm. Biofilm formation is a bacterial lifestyle, which offers a survival advantage through its protective matrix against host immune defense and antibiotic treatment. Interfering with biogenesis of adhesive organelles, bacterial communication or carbohydrate-mediated adhesion as anti-biofilm strategies are reviewed.
en
Anti-Bacterial Agents
Biofilms
Cross Infection
Gram-Negative Bacteria
Gram-Negative Bacterial Infections
Humans
New approaches to control infections: anti-biofilm strategies against gram-negative bacteria.
Article2018-06-13T21:23:47ZHospital-acquired bacterial infections, especially with Gram-negative pathogens, present a major threat due to the rapid spread of antibiotic-resistant strains. Targeting mechanisms of bacterial virulence has recently appeared as a promising new therapeutic paradigm. Biofilm formation is a bacterial lifestyle, which offers a survival advantage through its protective matrix against host immune defense and antibiotic treatment. Interfering with biogenesis of adhesive organelles, bacterial communication or carbohydrate-mediated adhesion as anti-biofilm strategies are reviewed.oai:repository.helmholtz-hzi.de:10033/3366982019-08-30T11:27:43Zcom_10033_620656col_10033_620658
Titz, Alexander
Ernst, Beat
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C 2.3, D-66123, Saarbrücken, Germany
2014-12-05T09:45:07Z
2014-12-05T09:45:07Z
2014-12-05
Mimetics of Sialyl Lewis<SUP>x</SUP>: The Pre-Organization of the Carboxylic Acid is Essential for Binding to Selectins 2007, 61 (4):194 CHIMIA International Journal for Chemistry
00094293
00000000
10.2533/chimia.2007.194
http://hdl.handle.net/10033/336698
CHIMIA International Journal for Chemistry
http://openurl.ingenta.com/content/xref?genre=article&issn=0009-4293&volume=61&issue=4&spage=194
Mimetics of Sialyl Lewis<SUP>x</SUP>: The Pre-Organization of the Carboxylic Acid is Essential for Binding to Selectins
Meetings and Proceedings2018-06-12T17:47:00Zoai:repository.helmholtz-hzi.de:10033/3445702019-08-30T11:30:58Zcom_10033_620656col_10033_620657
Stefanachi, Angela
Hanke, Nina
Pisani, Leonardo
Leonetti, Francesco
Nicolotti, Orazio
Catto, Marco
Cellamare, Saverio
Hartmann, Rolf W
Carotti, Angelo
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), PO Box 15 11 50, D-66041 Saarbrücken, Germany.
2015-02-18T13:39:43Z
2015-02-18T13:39:43Z
2015-01-07
Discovery of new 7-substituted-4-imidazolylmethyl coumarins and 4'-substituted-2-imidazolyl acetophenones open analogues as potent and selective inhibitors of steroid-11β-hydroxylase. 2015, 89:106-14 Eur J Med Chem
1768-3254
25462231
10.1016/j.ejmech.2014.10.021
http://hdl.handle.net/10033/344570
European journal of medicinal chemistry
Diseases triggered by an abnormally high level of cortisol (hypercortisolism), such as the Cushing's and metabolic syndromes, could be successfully tackled by inhibitors of CYP11B1, a steroidal cytochrome P450 enzyme that catalyzes the last hydroxylation step of the cortisol biosynthesis. Structural optimization of 7-(benzyloxy)-4-(1H-imidazol-1-ylmethyl)-2H-chromen-2-one 2, a selective aromatase inhibitor, afforded the 4-(1H-imidazol-1-ylmethyl)-7-{[3-(trifluoromethoxy)benzyl]oxy}-2H-chromen-2-one 7, with improved inhibitory potency at human CYP11B1 (IC50 = 5 nM) and an enhanced selectivity over human CYP11B2 (SIB = 25) compared to lead compound 2 (IC50 = 72 nM, SIB = 4.0) and metyrapone (IC50 = 15 nM, SIB = 4.8), a non-selective drug used in the therapy of the Cushing's syndrome. Structure-activity relationship studies allowed the design and optimization of a novel series of potent and selective compounds, that can be regarded as open analogues of 2H-chromen-2-one derivatives. Compound 23, 2-(1H-imidazol-1-yl)-1-(4-{[3(trifluoromethoxy)benzyl]oxy}phenyl) ethanone, was the most interesting inhibitor of the series displaying a high potency at CYP11B1 (IC50 = 15 nM), increased selectivities over CYP11B2 (SIB = 33), CYP19 (SIB = 390) and CYP17 (5% inhibition at 2.5 μM concentration).
en
Discovery of new 7-substituted-4-imidazolylmethyl coumarins and 4'-substituted-2-imidazolyl acetophenones open analogues as potent and selective inhibitors of steroid-11β-hydroxylase.
Article2018-06-13T05:42:39ZDiseases triggered by an abnormally high level of cortisol (hypercortisolism), such as the Cushing's and metabolic syndromes, could be successfully tackled by inhibitors of CYP11B1, a steroidal cytochrome P450 enzyme that catalyzes the last hydroxylation step of the cortisol biosynthesis. Structural optimization of 7-(benzyloxy)-4-(1H-imidazol-1-ylmethyl)-2H-chromen-2-one 2, a selective aromatase inhibitor, afforded the 4-(1H-imidazol-1-ylmethyl)-7-{[3-(trifluoromethoxy)benzyl]oxy}-2H-chromen-2-one 7, with improved inhibitory potency at human CYP11B1 (IC50 = 5 nM) and an enhanced selectivity over human CYP11B2 (SIB = 25) compared to lead compound 2 (IC50 = 72 nM, SIB = 4.0) and metyrapone (IC50 = 15 nM, SIB = 4.8), a non-selective drug used in the therapy of the Cushing's syndrome. Structure-activity relationship studies allowed the design and optimization of a novel series of potent and selective compounds, that can be regarded as open analogues of 2H-chromen-2-one derivatives. Compound 23, 2-(1H-imidazol-1-yl)-1-(4-{[3(trifluoromethoxy)benzyl]oxy}phenyl) ethanone, was the most interesting inhibitor of the series displaying a high potency at CYP11B1 (IC50 = 15 nM), increased selectivities over CYP11B2 (SIB = 33), CYP19 (SIB = 390) and CYP17 (5% inhibition at 2.5 μM concentration).oai:repository.helmholtz-hzi.de:10033/3445742019-08-30T11:30:58Zcom_10033_620656col_10033_620657
Allegretta, Giuseppe
Weidel, Elisabeth
Empting, Martin
Hartmann, Rolf W
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), PO Box 15 11 50, D-66041 Saarbrücken, Germany.
2015-02-18T13:48:22Z
2015-02-18T13:48:22Z
2015-01-27
Catechol-based substrates of chalcone synthase as a scaffold for novel inhibitors of PqsD. 2015, 90:351-9 Eur J Med Chem
1768-3254
25437621
10.1016/j.ejmech.2014.11.055
http://hdl.handle.net/10033/344574
European journal of medicinal chemistry
A new strategy for treating Pseudomonas aeruginosa infections could be disrupting the Pseudomonas Quinolone Signal (PQS) quorum sensing (QS) system. The goal is to impair communication among the cells and, hence, reduce the expression of virulence factors and the formation of biofilms. PqsD is an essential enzyme for the synthesis of PQS and shares some features with chalcone synthase (CHS2), an enzyme expressed in Medicago sativa. Both proteins are quite similar concerning the size of the active site, the catalytic residues and the electrostatic surface potential at the entrance of the substrate tunnel. Hence, we evaluated selected substrates of the vegetable enzyme as potential inhibitors of the bacterial protein. This similarity-guided approach led to the identification of a new class of PqsD inhibitors having a catechol structure as an essential feature for activity, a saturated linker with two or more carbons and an ester moiety bearing bulky substituents. The developed compounds showed PqsD inhibition with IC50 values in the single-digit micromolar range. The binding mode of these compounds was investigated by Surface Plasmon Resonance (SPR) experiments revealing that their interaction with the protein is not influenced by the presence of the anthranilic acid bound to active site cysteine. Importantly, some compounds reduced the signal molecule production in cellulo.
en
Catechol-based substrates of chalcone synthase as a scaffold for novel inhibitors of PqsD.
Article2018-06-12T16:54:45ZA new strategy for treating Pseudomonas aeruginosa infections could be disrupting the Pseudomonas Quinolone Signal (PQS) quorum sensing (QS) system. The goal is to impair communication among the cells and, hence, reduce the expression of virulence factors and the formation of biofilms. PqsD is an essential enzyme for the synthesis of PQS and shares some features with chalcone synthase (CHS2), an enzyme expressed in Medicago sativa. Both proteins are quite similar concerning the size of the active site, the catalytic residues and the electrostatic surface potential at the entrance of the substrate tunnel. Hence, we evaluated selected substrates of the vegetable enzyme as potential inhibitors of the bacterial protein. This similarity-guided approach led to the identification of a new class of PqsD inhibitors having a catechol structure as an essential feature for activity, a saturated linker with two or more carbons and an ester moiety bearing bulky substituents. The developed compounds showed PqsD inhibition with IC50 values in the single-digit micromolar range. The binding mode of these compounds was investigated by Surface Plasmon Resonance (SPR) experiments revealing that their interaction with the protein is not influenced by the presence of the anthranilic acid bound to active site cysteine. Importantly, some compounds reduced the signal molecule production in cellulo.oai:repository.helmholtz-hzi.de:10033/3452912019-08-30T11:31:23Zcom_10033_620656col_10033_620657
Grombein, Cornelia M
Hu, Qingzhong
Heim, Ralf
Rau, Sabrina
Zimmer, Christina
Hartmann, Rolf W
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Campus C23, D-66123 Saarbrücken, Germany.
2015-02-25T10:38:26Z
2015-02-25T10:38:26Z
2015-01-07
1-Phenylsulfinyl-3-(pyridin-3-yl)naphthalen-2-ols: a new class of potent and selective aldosterone synthase inhibitors. 2015, 89:597-605 Eur J Med Chem
1768-3254
25462268
10.1016/j.ejmech.2014.10.027
http://hdl.handle.net/10033/345291
European journal of medicinal chemistry
1-Phenylsulfinyl-3-(pyridin-3-yl)naphthalen-2-ols and related compounds were synthesized and evaluated for inhibition of aldosterone synthase (CYP11B2), a potential target for cardiovascular diseases associated with elevated plasma aldosterone levels like congestive heart failure and myocardial fibrosis. Introduction of substituents at the phenylsulfinyl moiety and changes of the substitution pattern at the naphthalene core were examined. Potent compounds were further examined for selectivity versus other important steroidogenic CYP enzymes, i.e. the highly homologous 11β-hydroxylase (CYP11B1), CYP17 and CYP19. The most potent compound (IC50 = 14 nM) discovered was the meta-trifluoromethoxy derivative 11, which also exhibited excellent selectivity toward CYP11B1 (SF = 415), and showed no inhibition of CYP17 and CYP19.
en
1-Phenylsulfinyl-3-(pyridin-3-yl)naphthalen-2-ols: a new class of potent and selective aldosterone synthase inhibitors.
Article2018-06-13T09:14:54Z1-Phenylsulfinyl-3-(pyridin-3-yl)naphthalen-2-ols and related compounds were synthesized and evaluated for inhibition of aldosterone synthase (CYP11B2), a potential target for cardiovascular diseases associated with elevated plasma aldosterone levels like congestive heart failure and myocardial fibrosis. Introduction of substituents at the phenylsulfinyl moiety and changes of the substitution pattern at the naphthalene core were examined. Potent compounds were further examined for selectivity versus other important steroidogenic CYP enzymes, i.e. the highly homologous 11β-hydroxylase (CYP11B1), CYP17 and CYP19. The most potent compound (IC50 = 14 nM) discovered was the meta-trifluoromethoxy derivative 11, which also exhibited excellent selectivity toward CYP11B1 (SF = 415), and showed no inhibition of CYP17 and CYP19.oai:repository.helmholtz-hzi.de:10033/3458232019-08-30T11:37:44Zcom_10033_620656col_10033_620657
Weidel, Elisabeth
Negri, Matthias
Empting, Martin
Hinsberger, Stefan
Hartmann, Rolf W
2015-03-02T13:39:14Z
2015-03-02T13:39:14Z
2014
Composing compound libraries for hit discovery--rationality-driven preselection or random choice by structural diversity? 2014, 6 (18):2057-72 Future Med Chem
1756-8927
25531968
10.4155/fmc.14.142
http://hdl.handle.net/10033/345823
Future medicinal chemistry
In order to identify new scaffolds for drug discovery, surface plasmon resonance is frequently used to screen structurally diverse libraries. Usually, hit rates are low and identification processes are time consuming. Hence, approaches which improve hit rates and, thus, reduce the library size are required.
en
Composing compound libraries for hit discovery--rationality-driven preselection or random choice by structural diversity?
Article2018-06-13T09:07:56ZIn order to identify new scaffolds for drug discovery, surface plasmon resonance is frequently used to screen structurally diverse libraries. Usually, hit rates are low and identification processes are time consuming. Hence, approaches which improve hit rates and, thus, reduce the library size are required.oai:repository.helmholtz-hzi.de:10033/3461342019-08-30T11:31:23Zcom_10033_620656col_10033_620657
Gargano, Emanuele M
Perspicace, Enrico
Hanke, Nina
Carotti, Angelo
Marchais-Oberwinkler, Sandrine
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University, Campus C2.3, D-66123 Saarbrücken, Germany.
2015-03-04T10:43:11Z
2015-03-04T10:43:11Z
2014-11-24
Metabolic stability optimization and metabolite identification of 2,5-thiophene amide 17β-hydroxysteroid dehydrogenase type 2 inhibitors. 2014, 87:203-19 Eur J Med Chem
1768-3254
25259513
10.1016/j.ejmech.2014.09.061
http://hdl.handle.net/10033/346134
European journal of medicinal chemistry
17β-HSD2 is a promising new target for the treatment of osteoporosis. In this paper, a rational strategy to overcome the metabolic liability in the 2,5-thiophene amide class of 17β-HSD2 inhibitors is described, and the biological activity of the new inhibitors. Applying different strategies, as lowering the cLogP or modifying the structures of the molecules, compounds 27, 31 and 35 with strongly improved metabolic stability were obtained. For understanding biotransformation in the 2,5-thiophene amide class the main metabolic pathways of three properly selected compounds were elucidated.
en
Metabolic stability optimization and metabolite identification of 2,5-thiophene amide 17β-hydroxysteroid dehydrogenase type 2 inhibitors.
Article2018-06-13T00:28:29Z17β-HSD2 is a promising new target for the treatment of osteoporosis. In this paper, a rational strategy to overcome the metabolic liability in the 2,5-thiophene amide class of 17β-HSD2 inhibitors is described, and the biological activity of the new inhibitors. Applying different strategies, as lowering the cLogP or modifying the structures of the molecules, compounds 27, 31 and 35 with strongly improved metabolic stability were obtained. For understanding biotransformation in the 2,5-thiophene amide class the main metabolic pathways of three properly selected compounds were elucidated.oai:repository.helmholtz-hzi.de:10033/3466022019-08-30T11:27:46Zcom_10033_620656col_10033_620657
Beber, T C
Andrade, D F
Kann, B
Fontana, M C
Coradini, K
Windbergs, M
Beck, R C R
Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany.
2015-03-13T14:53:24Z
2015-03-13T14:53:24Z
2014-11
Submicron polymeric particles prepared by vibrational spray-drying: Semisolid formulation and skin penetration/permeation studies. 2014, 88 (3):602-13 Eur J Pharm Biopharm
1873-3441
25078859
10.1016/j.ejpb.2014.07.008
http://hdl.handle.net/10033/346602
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnik e.V
Topical glucocorticoids (TG) such as dexamethasone (DEX) have been used for decades for the treatment of skin diseases. However, TG present well-documented side effects and their delivery to the skin is often insufficient. Therefore, many efforts have been undergone to improve the amount of drug delivered to the skin and to reduce side effects at the same time. In this work, the feasibility of DEX-submicron polymeric particles (SP) prepared by vibrational spray-drying as an approach to overcome the challenges associated with the topical administration of this drug class was evaluated. DEX was homogeneously dispersed in the SP matrix, according to confocal Raman microscopy analysis. Drug-loaded SP were incorporated into the oil phase of oil-in-water emulsions (creams). The formulation containing polymeric submicron particles (C-SP) showed controlled drug release kinetics and a significant drug accumulation in skin compared to formulations containing non-polymeric particles or free drug. DEX accumulation in the stratum corneum was evaluated by tape stripping and a depot effect over time was observed for C-SP, while the formulation containing the free drug showed a decrease over time. Similarly, C-SP presented higher drug retention in epidermis and dermis in skin penetration studies performed on pig skin in Franz diffusion cells, while drug permeation into the receptor compartment was negligible. It was demonstrated, for the first time, the advantageous application of submicron polymeric particles obtained by vibrational spray-drying in semisolid formulations for cutaneous administration to overcome challenges related to the therapy with TG such as DEX.
en
Submicron polymeric particles prepared by vibrational spray-drying: Semisolid formulation and skin penetration/permeation studies.
Article2018-06-13T04:00:57ZTopical glucocorticoids (TG) such as dexamethasone (DEX) have been used for decades for the treatment of skin diseases. However, TG present well-documented side effects and their delivery to the skin is often insufficient. Therefore, many efforts have been undergone to improve the amount of drug delivered to the skin and to reduce side effects at the same time. In this work, the feasibility of DEX-submicron polymeric particles (SP) prepared by vibrational spray-drying as an approach to overcome the challenges associated with the topical administration of this drug class was evaluated. DEX was homogeneously dispersed in the SP matrix, according to confocal Raman microscopy analysis. Drug-loaded SP were incorporated into the oil phase of oil-in-water emulsions (creams). The formulation containing polymeric submicron particles (C-SP) showed controlled drug release kinetics and a significant drug accumulation in skin compared to formulations containing non-polymeric particles or free drug. DEX accumulation in the stratum corneum was evaluated by tape stripping and a depot effect over time was observed for C-SP, while the formulation containing the free drug showed a decrease over time. Similarly, C-SP presented higher drug retention in epidermis and dermis in skin penetration studies performed on pig skin in Franz diffusion cells, while drug permeation into the receptor compartment was negligible. It was demonstrated, for the first time, the advantageous application of submicron polymeric particles obtained by vibrational spray-drying in semisolid formulations for cutaneous administration to overcome challenges related to the therapy with TG such as DEX.oai:repository.helmholtz-hzi.de:10033/3469152019-08-30T11:28:23Zcom_10033_620656col_10033_620657
Grombein, Cornelia M
Hu, Qingzhong
Rau, Sabrina
Zimmer, Christina
Hartmann, Rolf W
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Campus C2 3, D-66123 Saarbrücken, Germany.
2015-03-19T15:21:26Z
2015-03-19T15:21:26Z
2015-01-27
Heteroatom insertion into 3,4-dihydro-1H-quinolin-2-ones leads to potent and selective inhibitors of human and rat aldosterone synthase. 2015, 90:788-96 Eur J Med Chem
1768-3254
25528333
10.1016/j.ejmech.2014.12.022
http://hdl.handle.net/10033/346915
European journal of medicinal chemistry
Aldosterone synthase (CYP11B2) catalyzes the conversion of 11-deoxycorticosterone to aldosterone via corticosterone and 18-hydroxycorticosterone. CYP11B2 is regarded as a new target for several cardiovascular diseases which are associated with chronically elevated aldosterone levels such as hypertension, congestive heart failure and myocardial fibrosis. In this paper, we optimized heterocycle substituted 3,4-dihydropyridin-2(1H)-ones as CYP11B inhibitors by systematic introduction of heteroatoms and by bioisosteric exchange of the lactame moiety by a sultame moiety. The most promising compounds regarding inhibition of human CYP11B2 and selectivity versus human enzymes CYP11B1, CYP17, and CYP19 were tested for inhibition of rat CYP11B2. Thus, we discovered compounds 4 and 9 which show potent inhibition of hCYP11B2 (IC50 < 1 nM) and the corresponding rat enzyme (4: 64%, 9: 51% inhibition, at 2 μM).
en
Heteroatom insertion into 3,4-dihydro-1H-quinolin-2-ones leads to potent and selective inhibitors of human and rat aldosterone synthase.
Article2018-06-12T17:22:57ZAldosterone synthase (CYP11B2) catalyzes the conversion of 11-deoxycorticosterone to aldosterone via corticosterone and 18-hydroxycorticosterone. CYP11B2 is regarded as a new target for several cardiovascular diseases which are associated with chronically elevated aldosterone levels such as hypertension, congestive heart failure and myocardial fibrosis. In this paper, we optimized heterocycle substituted 3,4-dihydropyridin-2(1H)-ones as CYP11B inhibitors by systematic introduction of heteroatoms and by bioisosteric exchange of the lactame moiety by a sultame moiety. The most promising compounds regarding inhibition of human CYP11B2 and selectivity versus human enzymes CYP11B1, CYP17, and CYP19 were tested for inhibition of rat CYP11B2. Thus, we discovered compounds 4 and 9 which show potent inhibition of hCYP11B2 (IC50 < 1 nM) and the corresponding rat enzyme (4: 64%, 9: 51% inhibition, at 2 μM).oai:repository.helmholtz-hzi.de:10033/3470622019-08-30T11:26:13Zcom_10033_620656col_10033_620657
Laggai, Stephan
Kessler, Sonja M
Boettcher, Stefan
Lebrun, Valérie
Gemperlein, Katja
Lederer, Eva
Leclercq, Isabelle A
Mueller, Rolf
Hartmann, Rolf W
Haybaeck, Johannes
Kiemer, Alexandra K
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarbrücken, Germany.
2015-03-24T12:10:17Z
2015-03-24T12:10:17Z
2014-04-22
The IGF2 mRNA binding protein p62/IGF2BP2-2 induces fatty acid elongation as a critical feature of steatosis. 2014, 55 (6):1087-1097 J. Lipid Res.
0022-2275
24755648
10.1194/jlr.M045500
http://hdl.handle.net/10033/347062
Journal of lipid research
Liver-specific overexpression of the insulin-like growth factor 2 (IGF2) mRNA binding protein p62/IGF2BP2-2 induces a fatty liver, which highly expresses IGF2. Because IGF2 expression is elevated in patients with steatohepatitis, the aim of our study was to elucidate the role and interconnection of p62 and IGF2 in lipid metabolism. Expression of p62 and IGF2 highly correlated in human liver disease. p62 induced an elevated ratio of C18:C16 and increased fatty acid elongase 6 (ELOVL6) protein, the enzyme catalyzing the elongation of C16 to C18 fatty acids and promoting nonalcoholic steatohepatitis in mice and humans. The p62 overexpression induced the activation of the ELOVL6 transcriptional activator sterol regulatory element binding transcription factor 1 (SREBF1). Recombinant IGF2 induced the nuclear translocation of SREBF1 and a neutralizing IGF2 antibody reduced ELOVL6 and mature SREBF1 protein levels. Concordantly, p62 and IGF2 correlated with ELOVL6 in human livers. Decreased palmitoyl-CoA levels, as found in p62 transgenic livers, can explain the lipogenic action of ELOVL6. Accordingly, p62 represents an inducer of hepatic C18 fatty acid production via a SREBF1-dependent induction of ELOVL6. These findings underline the detrimental role of p62 in liver disease.
ENG
The IGF2 mRNA binding protein p62/IGF2BP2-2 induces fatty acid elongation as a critical feature of steatosis.
Article2015-06-15T00:00:00ZLiver-specific overexpression of the insulin-like growth factor 2 (IGF2) mRNA binding protein p62/IGF2BP2-2 induces a fatty liver, which highly expresses IGF2. Because IGF2 expression is elevated in patients with steatohepatitis, the aim of our study was to elucidate the role and interconnection of p62 and IGF2 in lipid metabolism. Expression of p62 and IGF2 highly correlated in human liver disease. p62 induced an elevated ratio of C18:C16 and increased fatty acid elongase 6 (ELOVL6) protein, the enzyme catalyzing the elongation of C16 to C18 fatty acids and promoting nonalcoholic steatohepatitis in mice and humans. The p62 overexpression induced the activation of the ELOVL6 transcriptional activator sterol regulatory element binding transcription factor 1 (SREBF1). Recombinant IGF2 induced the nuclear translocation of SREBF1 and a neutralizing IGF2 antibody reduced ELOVL6 and mature SREBF1 protein levels. Concordantly, p62 and IGF2 correlated with ELOVL6 in human livers. Decreased palmitoyl-CoA levels, as found in p62 transgenic livers, can explain the lipogenic action of ELOVL6. Accordingly, p62 represents an inducer of hepatic C18 fatty acid production via a SREBF1-dependent induction of ELOVL6. These findings underline the detrimental role of p62 in liver disease.oai:repository.helmholtz-hzi.de:10033/5562022019-08-30T11:28:51Zcom_10033_620656col_10033_620657
Sahner, J Henning
Empting, Martin
Kamal, Ahmed
Weidel, Elisabeth
Groh, Matthias
Börger, Carsten
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University & Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Department of Drug Design and Optimization, Campus C2 3, 66123 Saarbrücken, Germany.
2015-06-03T12:40:11Z
2015-06-03T12:40:11Z
2015-05-26
Exploring the chemical space of ureidothiophene-2-carboxylic acids as inhibitors of the quorum sensing enzyme PqsD from Pseudomonas aeruginosa. 2015, 96:14-21 Eur J Med Chem
1768-3254
25874327
10.1016/j.ejmech.2015.04.007
http://hdl.handle.net/10033/556202
European journal of medicinal chemistry
Pseudomonas aeruginosa employs a quorum sensing (QS) communication system that makes use of small diffusible molecules. Among other effects, the QS system coordinates the formation of biofilm which decisively contributes to difficulties in the therapy of Pseudomonas infections. The present work deals with the structure-activity exploration of ureidothiophene-2-carboxylic acids as inhibitors of PqsD, a key enzyme in the biosynthetic pathway of signal molecules in the Pseudomonas QS system. We describe an improvement of the inhibitory activity by successfully combining features from two different PqsD inhibitor classes. Furthermore the functional groups, which are responsible for the inhibitory potency, were identified. Moreover, the inability of the new inhibitors, to prevent signal molecule formation in whole cell assays, is discussed.
en
Exploring the chemical space of ureidothiophene-2-carboxylic acids as inhibitors of the quorum sensing enzyme PqsD from Pseudomonas aeruginosa.
Article2018-06-12T21:49:49ZPseudomonas aeruginosa employs a quorum sensing (QS) communication system that makes use of small diffusible molecules. Among other effects, the QS system coordinates the formation of biofilm which decisively contributes to difficulties in the therapy of Pseudomonas infections. The present work deals with the structure-activity exploration of ureidothiophene-2-carboxylic acids as inhibitors of PqsD, a key enzyme in the biosynthetic pathway of signal molecules in the Pseudomonas QS system. We describe an improvement of the inhibitory activity by successfully combining features from two different PqsD inhibitor classes. Furthermore the functional groups, which are responsible for the inhibitory potency, were identified. Moreover, the inability of the new inhibitors, to prevent signal molecule formation in whole cell assays, is discussed.oai:repository.helmholtz-hzi.de:10033/5562032019-08-30T11:28:51Zcom_10033_620656col_10033_620657
Hu, Qingzhong
Kunde, Jessica
Hanke, Nina
Hartmann, Rolf W
Pharmaceutical and Medicinal Chemistry, Saarland University, Campus C2.3, D-66123 Saarbrücken, Germany.
2015-06-03T12:52:31Z
2015-06-03T12:52:31Z
2015-05-26
Identification of 4-(4-nitro-2-phenethoxyphenyl)pyridine as a promising new lead for discovering inhibitors of both human and rat 11β-Hydroxylase. 2015, 96:139-50 Eur J Med Chem
1768-3254
25874338
10.1016/j.ejmech.2015.04.013
http://hdl.handle.net/10033/556203
European journal of medicinal chemistry
The inhibition of 11β-hydroxylase is a promising strategy for the treatment of Cushing's syndrome, in particular for the recurrent and subclinical cases. To achieve proof of concept in rats, efforts were paid to identify novel lead compounds inhibiting both human and rat CYP11B1. Modifications on a potent promiscuous inhibitor of hCYP11B1, hCYP11B2 and hCYP19 (compound IV) that exhibited moderate rCYP11B1 inhibition led to compound 8 as a new promising lead compound. Significant improvements compared to starting point IV were achieved regarding inhibitory potency against both human and rat CYP11B1 (IC50 values of 2 and 163 nM, respectively) as well as selectivity over hCYP19 (IC50 = 1900 nM). Accordingly, compound 8 was around 7- and 28-fold more potent than metyrapone regarding the inhibition of human and rat CYP11B1 and exhibited a comparable selectivity over hCYP11B2 (SF of 3.5 vs 4.9). With further optimizations on this new lead compound 8, drug candidates with satisfying profiles are expected to be discovered.
en
Identification of 4-(4-nitro-2-phenethoxyphenyl)pyridine as a promising new lead for discovering inhibitors of both human and rat 11β-Hydroxylase.
Article2018-06-13T00:51:48ZThe inhibition of 11β-hydroxylase is a promising strategy for the treatment of Cushing's syndrome, in particular for the recurrent and subclinical cases. To achieve proof of concept in rats, efforts were paid to identify novel lead compounds inhibiting both human and rat CYP11B1. Modifications on a potent promiscuous inhibitor of hCYP11B1, hCYP11B2 and hCYP19 (compound IV) that exhibited moderate rCYP11B1 inhibition led to compound 8 as a new promising lead compound. Significant improvements compared to starting point IV were achieved regarding inhibitory potency against both human and rat CYP11B1 (IC50 values of 2 and 163 nM, respectively) as well as selectivity over hCYP19 (IC50 = 1900 nM). Accordingly, compound 8 was around 7- and 28-fold more potent than metyrapone regarding the inhibition of human and rat CYP11B1 and exhibited a comparable selectivity over hCYP11B2 (SF of 3.5 vs 4.9). With further optimizations on this new lead compound 8, drug candidates with satisfying profiles are expected to be discovered.oai:repository.helmholtz-hzi.de:10033/5567812019-08-30T11:29:17Zcom_10033_620656col_10033_620658
Hofmann, Anna
Sommer, Roman
Hauck, Dirk
Stifel, Julia
Göttker-Schnetmann, Inigo
Titz, Alexander
hemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany.
2015-06-11T14:17:27Z
2015-06-11T14:17:27Z
2015-05-05
Synthesis of mannoheptose derivatives and their evaluation as inhibitors of the lectin LecB from the opportunistic pathogen Pseudomonas aeruginosa. 2015, 412:34-42 Carbohydr. Res.
1873-426X
26004349
10.1016/j.carres.2015.04.010
http://hdl.handle.net/10033/556781
Carbohydrate research
Biofilm formation and chronic infections with Pseudomonas aeruginosa depend on lectins produced by the bacterium. The bacterial C-type lectin LecB binds to the two monosaccharides l-fucose and d-mannose and conjugates thereof. Previously, d-mannose derivatives with amide and sulfonamide substituents at C6 were reported as potent inhibitors of the bacterial lectin LecB and LecB-mediated bacterial surface adhesion. Because d-mannose establishes a hydrogen bond via its 6-OH group with Ser23 of LecB in the crystal structure and may be beneficial for binding affinity, we extended d-mannose and synthesized mannoheptoses bearing the free 6-OH group as well as amido and sulfonamido-substituents at C7. Two series of diastereomeric mannoheptoses were synthesized and the stereochemistry was determined by X-ray crystallography. The potency of the mannoheptoses as LecB inhibitors was assessed in a competitive binding assay. The data reveal a diastereoselectivity of LecB for (6S)-mannoheptose derivatives with increased activity over methyl α-d-mannoside.
ENG
Synthesis of mannoheptose derivatives and their evaluation as inhibitors of the lectin LecB from the opportunistic pathogen Pseudomonas aeruginosa.
Article2016-08-15T00:00:00ZBiofilm formation and chronic infections with Pseudomonas aeruginosa depend on lectins produced by the bacterium. The bacterial C-type lectin LecB binds to the two monosaccharides l-fucose and d-mannose and conjugates thereof. Previously, d-mannose derivatives with amide and sulfonamide substituents at C6 were reported as potent inhibitors of the bacterial lectin LecB and LecB-mediated bacterial surface adhesion. Because d-mannose establishes a hydrogen bond via its 6-OH group with Ser23 of LecB in the crystal structure and may be beneficial for binding affinity, we extended d-mannose and synthesized mannoheptoses bearing the free 6-OH group as well as amido and sulfonamido-substituents at C7. Two series of diastereomeric mannoheptoses were synthesized and the stereochemistry was determined by X-ray crystallography. The potency of the mannoheptoses as LecB inhibitors was assessed in a competitive binding assay. The data reveal a diastereoselectivity of LecB for (6S)-mannoheptose derivatives with increased activity over methyl α-d-mannoside.oai:repository.helmholtz-hzi.de:10033/5610552019-08-30T11:35:39Zcom_10033_620656col_10033_620657
Zielonka, Stefan
Empting, Martin
Könning, Doreen
Grzeschik, Julius
Krah, Simon
Becker, Stefan
Dickgießer, Stephan
Kolmar, Harald
2Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University, Campus C2.3, 66123 Saarbrücken, Germany.
2015-07-27T09:50:38Z
2015-07-27T09:50:38Z
2015-08
The Shark Strikes Twice: Hypervariable Loop 2 of Shark IgNAR Antibody Variable Domains and Its Potential to Function as an Autonomous Paratope. 2015, 17 (4):386-92 Mar. Biotechnol.
1436-2236
26003538
10.1007/s10126-015-9642-z
http://hdl.handle.net/10033/561055
Marine biotechnology (New York, N.Y.)
In this present study, we engineered hypervariable loop 2 (HV2) of the IgNAR variable domain in a way that it solely facilitates antigen binding, potentially functioning as an autonomous paratope. For this, the surface-exposed loop corresponding to HV2 was diversified and antigen-specific variable domain of IgNAR antibody (vNAR) molecules were isolated by library screening using yeast surface display (YSD) as platform technology. An epithelial cell adhesion molecule (EpCAM)-specific vNAR was used as starting material, and nine residues in HV2 were randomized. Target-specific clones comprising a new HV2-mediated paratope were isolated against cluster of differentiation 3ε (CD3ε) and human Fcγ while retaining high affinity for EpCAM. Essentially, we demonstrate that a new paratope comprising moderate affinities against a given target molecule can be engineered into the vNAR scaffold that acts independent of the original antigen-binding site, composed of complementarity-determining region 3 (CDR3) and CDR1.
en
The Shark Strikes Twice: Hypervariable Loop 2 of Shark IgNAR Antibody Variable Domains and Its Potential to Function as an Autonomous Paratope.
Article2016-08-02T00:00:00ZIn this present study, we engineered hypervariable loop 2 (HV2) of the IgNAR variable domain in a way that it solely facilitates antigen binding, potentially functioning as an autonomous paratope. For this, the surface-exposed loop corresponding to HV2 was diversified and antigen-specific variable domain of IgNAR antibody (vNAR) molecules were isolated by library screening using yeast surface display (YSD) as platform technology. An epithelial cell adhesion molecule (EpCAM)-specific vNAR was used as starting material, and nine residues in HV2 were randomized. Target-specific clones comprising a new HV2-mediated paratope were isolated against cluster of differentiation 3ε (CD3ε) and human Fcγ while retaining high affinity for EpCAM. Essentially, we demonstrate that a new paratope comprising moderate affinities against a given target molecule can be engineered into the vNAR scaffold that acts independent of the original antigen-binding site, composed of complementarity-determining region 3 (CDR3) and CDR1.oai:repository.helmholtz-hzi.de:10033/5759332019-08-30T11:33:30Zcom_10033_620656col_10033_620657
Müller, Stefan
Rachid, Shwan
Hoffmann, Thomas
Surup, Frank
Volz, Carsten
Zaburannyi, Nestor
Müller, Rolf
Helmholtz Institute for Pharmaceutical Research Saarland,Saarbru¨ cken, Saarland 66123, Germany.
2015-08-25T13:54:50Z
2015-08-25T13:54:50Z
2014-07-17
Biosynthesis of crocacin involves an unusual hydrolytic release domain showing similarity to condensation domains. 2014, 21 (7):855-65 Chem. Biol.
1879-1301
24981773
10.1016/j.chembiol.2014.05.012
http://hdl.handle.net/10033/575933
Chemistry & biology
The crocacins are potent antifungal and cytotoxic natural compounds from myxobacteria of the genus Chondromyces. Although total synthesis approaches have been reported, the molecular and biochemical basis guiding the formation of the linear crocacin scaffold has remained unknown. Along with the identification and functional analysis of the crocacin biosynthetic gene cluster from Chondromyces crocatus Cm c5, we here present the identification and biochemical characterization of an unusual chain termination domain homologous to condensation domains responsible for hydrolytic release of the product from the assembly line. In particular, gene inactivation studies and in vitro experiments using the heterologously produced domain CroK-C2 confirm this surprising role giving rise to the linear carboxylic acid. Additionally, we determined the kinetic parameters of CroK-C2 by monitoring hydrolytic cleavage of the substrate mimic N-acetylcysteaminyl-crocacin B using an innovative high-performance liquid chromatography mass spectrometry-based assay.
en
Biological Products
Genetic Engineering
Hydrolysis
Models, Biological
Molecular Sequence Data
Multigene Family
Myxococcales
Peptide Synthases
Polyenes
Protein Structure, Tertiary
Biosynthesis of crocacin involves an unusual hydrolytic release domain showing similarity to condensation domains.
Article2018-06-12T17:30:50ZThe crocacins are potent antifungal and cytotoxic natural compounds from myxobacteria of the genus Chondromyces. Although total synthesis approaches have been reported, the molecular and biochemical basis guiding the formation of the linear crocacin scaffold has remained unknown. Along with the identification and functional analysis of the crocacin biosynthetic gene cluster from Chondromyces crocatus Cm c5, we here present the identification and biochemical characterization of an unusual chain termination domain homologous to condensation domains responsible for hydrolytic release of the product from the assembly line. In particular, gene inactivation studies and in vitro experiments using the heterologously produced domain CroK-C2 confirm this surprising role giving rise to the linear carboxylic acid. Additionally, we determined the kinetic parameters of CroK-C2 by monitoring hydrolytic cleavage of the substrate mimic N-acetylcysteaminyl-crocacin B using an innovative high-performance liquid chromatography mass spectrometry-based assay.oai:repository.helmholtz-hzi.de:10033/6209482019-08-30T11:36:32Zcom_10033_620656col_10033_620657
Steinbach, Anke
Maurer, Christine K
Weidel, Elisabeth
Henn, Claudia
Brengel, Christian
Hartmann, Rolf W
Negri, Matthias
2017-06-15T08:44:04Z
2017-06-15T08:44:04Z
2013-08-01
2015-09-04T08:24:33Z
BMC Biophysics. 2013 Aug 01;6(1):10
http://dx.doi.org/10.1186/2046-1682-6-10
http://hdl.handle.net/10033/620948
Abstract Background PQS (P seudomonas Quinolone Signal) and its precursor HHQ are signal molecules of the P. aeruginosa quorum sensing system. They explicate their role in mammalian pathogenicity by binding to the receptor PqsR that induces virulence factor production and biofilm formation. The enzyme PqsD catalyses the biosynthesis of HHQ. Results Enzyme kinetic analysis and surface plasmon resonance (SPR) biosensor experiments were used to determine mechanism and substrate order of the biosynthesis. Comparative analysis led to the identification of domains involved in functionality of PqsD. A kinetic cycle was set up and molecular dynamics (MD) simulations were used to study the molecular bases of the kinetics of PqsD. Trajectory analysis, pocket volume measurements, binding energy estimations and decompositions ensured insights into the binding mode of the substrates anthraniloyl-CoA and β-ketodecanoic acid. Conclusions Enzyme kinetics and SPR experiments hint at a ping-pong mechanism for PqsD with ACoA as first substrate. Trajectory analysis of different PqsD complexes evidenced ligand-dependent induced-fit motions affecting the modified ACoA funnel access to the exposure of a secondary channel. A tunnel-network is formed in which Ser317 plays an important role by binding to both substrates. Mutagenesis experiments resulting in the inactive S317F mutant confirmed the importance of this residue. Two binding modes for β-ketodecanoic acid were identified with distinct catalytic mechanism preferences.
Molecular basis of HHQ biosynthesis: molecular dynamics simulations, enzyme kinetic and surface plasmon resonance studies
Journal Article
en
Steinbach et al.; licensee BioMed Central Ltd.2018-06-13T05:30:52ZAbstract
Background
PQS (P
seudomonas
Quinolone Signal) and its precursor HHQ are signal molecules of the P. aeruginosa quorum sensing system. They explicate their role in mammalian pathogenicity by binding to the receptor PqsR that induces virulence factor production and biofilm formation. The enzyme PqsD catalyses the biosynthesis of HHQ.
Results
Enzyme kinetic analysis and surface plasmon resonance (SPR) biosensor experiments were used to determine mechanism and substrate order of the biosynthesis. Comparative analysis led to the identification of domains involved in functionality of PqsD. A kinetic cycle was set up and molecular dynamics (MD) simulations were used to study the molecular bases of the kinetics of PqsD. Trajectory analysis, pocket volume measurements, binding energy estimations and decompositions ensured insights into the binding mode of the substrates anthraniloyl-CoA and β-ketodecanoic acid.
Conclusions
Enzyme kinetics and SPR experiments hint at a ping-pong mechanism for PqsD with ACoA as first substrate. Trajectory analysis of different PqsD complexes evidenced ligand-dependent induced-fit motions affecting the modified ACoA funnel access to the exposure of a secondary channel. A tunnel-network is formed in which Ser317 plays an important role by binding to both substrates. Mutagenesis experiments resulting in the inactive S317F mutant confirmed the importance of this residue. Two binding modes for β-ketodecanoic acid were identified with distinct catalytic mechanism preferences.oai:repository.helmholtz-hzi.de:10033/5774382019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Adam, Oliver
Zimmer, Christina
Hanke, Nina
Hartmann, Rolf W
Klemmer, Birgit
Böhm, Michael
Laufs, Ulrich
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany.
2015-09-17T15:17:44Z
2015-09-17T15:17:44Z
2015-08
Inhibition of aldosterone synthase (CYP11B2) by torasemide prevents atrial fibrosis and atrial fibrillation in mice. 2015, 85:140-50 J. Mol. Cell. Cardiol.
1095-8584
26047574
10.1016/j.yjmcc.2015.05.019
http://hdl.handle.net/10033/577438
Journal of molecular and cellular cardiology
Loop diuretics are used for fluid control in patients with heart failure. Furosemide and torasemide may exert differential effects on myocardial fibrosis. Here, we studied the effects of torasemide and furosemide on atrial fibrosis and remodeling during atrial fibrillation. In primary neonatal cardiac fibroblasts, torasemide (50μM, 24h) but not furosemide (50μM, 24h) reduced the expression of connective tissue growth factor (CTGF; 65±6%) and the pro-fibrotic miR-21 (44±23%), as well as the expression of lysyl oxidase (LOX; 57±8%), a regulator of collagen crosslinking. Mineralocorticoid receptor (MR) expression and activity were not altered. Torasemide but not furosemide inhibited human aldosterone synthase (CYP11B2) activity in transfected lung fibroblasts (V79MZ cells) by 75±1.8%. The selective CYP11B2 inhibitor SL242 mimicked the torasemide effects. Mice with cardiac overexpression of Rac1 GTPase (RacET), which develop atrial fibrosis and spontaneous AF with aging, were treated long-term (8months) with torasemide (10mg/kg/day), furosemide (40mg/kg/day) or vehicle. Treatment with torasemide but not furosemide prevented atrial fibrosis in RacET as well as the up-regulation of CTGF, LOX, and miR-2, whereas MR expression and activity remained unaffected. These effects correlated with a reduced prevalence of atrial fibrillation (33% RacET+Tora vs. 80% RacET). Torasemide but not furosemide inhibits CYP11B2 activity and reduces the expression of CTGF, LOX, and miR-21. These effects are associated with prevention of atrial fibrosis and a reduced prevalence of atrial fibrillation in mice.
en
Inhibition of aldosterone synthase (CYP11B2) by torasemide prevents atrial fibrosis and atrial fibrillation in mice.
Article2016-08-15T00:00:00ZLoop diuretics are used for fluid control in patients with heart failure. Furosemide and torasemide may exert differential effects on myocardial fibrosis. Here, we studied the effects of torasemide and furosemide on atrial fibrosis and remodeling during atrial fibrillation. In primary neonatal cardiac fibroblasts, torasemide (50μM, 24h) but not furosemide (50μM, 24h) reduced the expression of connective tissue growth factor (CTGF; 65±6%) and the pro-fibrotic miR-21 (44±23%), as well as the expression of lysyl oxidase (LOX; 57±8%), a regulator of collagen crosslinking. Mineralocorticoid receptor (MR) expression and activity were not altered. Torasemide but not furosemide inhibited human aldosterone synthase (CYP11B2) activity in transfected lung fibroblasts (V79MZ cells) by 75±1.8%. The selective CYP11B2 inhibitor SL242 mimicked the torasemide effects. Mice with cardiac overexpression of Rac1 GTPase (RacET), which develop atrial fibrosis and spontaneous AF with aging, were treated long-term (8months) with torasemide (10mg/kg/day), furosemide (40mg/kg/day) or vehicle. Treatment with torasemide but not furosemide prevented atrial fibrosis in RacET as well as the up-regulation of CTGF, LOX, and miR-2, whereas MR expression and activity remained unaffected. These effects correlated with a reduced prevalence of atrial fibrillation (33% RacET+Tora vs. 80% RacET). Torasemide but not furosemide inhibits CYP11B2 activity and reduces the expression of CTGF, LOX, and miR-21. These effects are associated with prevention of atrial fibrosis and a reduced prevalence of atrial fibrillation in mice.oai:repository.helmholtz-hzi.de:10033/5796122019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Abdelsamie, Ahmed S
Bey, Emmanuel
Gargano, Emanuele M
van Koppen, Chris J
Empting, Martin
Frotscher, Martin
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Campus C23, D-66123 Saarbrücken, Germany.
2015-10-14T08:24:30Z
2015-10-14T08:24:30Z
2015-10-20
Towards the evaluation in an animal disease model: Fluorinated 17β-HSD1 inhibitors showing strong activity towards both the human and the rat enzyme. 2015, 103:56-68 Eur J Med Chem
1768-3254
26322835
10.1016/j.ejmech.2015.08.030
http://hdl.handle.net/10033/579612
European journal of medicinal chemistry
17β-Estradiol (E2), the most potent human estrogen, is known to be involved in the etiology of estrogen-dependent diseases (EDD) like breast cancer and endometriosis. 17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyses the last step of E2 biosynthesis and is thus a promising target for the treatment of EDD. The previously described bicyclic substituted hydroxyphenylmethanones (BSHs) display high inhibitory potency towards human 17β-HSD1, but marginal activity towards rodent 17β-HSD1, precluding a proof of principle study in an animal endometriosis model. The aim of this work was to perform structural optimizations in the BSHs class to enhance inhibitory activity against rodent (mouse and rat) 17β-HSD1 while maintaining activity against the human enzyme. The introduction of fluorine atoms on the benzoyl moiety resulted in compounds with the desired properties. Molecular docking and homology modeling were applied to elucidate the binding mode and interspecies differences in activity. Compound 33 is the most potent inhibitor of both human and rat 17β-HSD1 up to date (IC50 = 2 nM and 97 nM, respectively).
en
Towards the evaluation in an animal disease model: Fluorinated 17β-HSD1 inhibitors showing strong activity towards both the human and the rat enzyme.
Article2016-11-01T00:00:00Z17β-Estradiol (E2), the most potent human estrogen, is known to be involved in the etiology of estrogen-dependent diseases (EDD) like breast cancer and endometriosis. 17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyses the last step of E2 biosynthesis and is thus a promising target for the treatment of EDD. The previously described bicyclic substituted hydroxyphenylmethanones (BSHs) display high inhibitory potency towards human 17β-HSD1, but marginal activity towards rodent 17β-HSD1, precluding a proof of principle study in an animal endometriosis model. The aim of this work was to perform structural optimizations in the BSHs class to enhance inhibitory activity against rodent (mouse and rat) 17β-HSD1 while maintaining activity against the human enzyme. The introduction of fluorine atoms on the benzoyl moiety resulted in compounds with the desired properties. Molecular docking and homology modeling were applied to elucidate the binding mode and interspecies differences in activity. Compound 33 is the most potent inhibitor of both human and rat 17β-HSD1 up to date (IC50 = 2 nM and 97 nM, respectively).oai:repository.helmholtz-hzi.de:10033/5931012019-08-30T11:34:17Zcom_10033_620656col_10033_620657
Thomann, Andreas
Eberhard, Jens
Allegretta, Giuseppe
Empting, Martin
Hartmann, Rolf
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany.
Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University
Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University
Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University
Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University
Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University
2016-01-08T15:36:42Z
2016-01-08T15:36:42Z
2015-10-21
Mild and Catalyst-Free Microwave-Assisted Synthesis of 4,6-Disubstituted 2-Methylthiopyrimidines – Exploiting Tetrazole as an Efficient Leaving Group 2015, 26 (18):2606 Synlett
0936-5214
1437-2096
10.1055/s-0035-1560577
http://hdl.handle.net/10033/593101
Synlett
http://www.thieme-connect.de/DOI/DOI?10.1055/s-0035-1560577
Mild and Catalyst-Free Microwave-Assisted Synthesis of 4,6-Disubstituted 2-Methylthiopyrimidines – Exploiting Tetrazole as an Efficient Leaving Group
Article2016-11-15T00:00:00Zoai:repository.helmholtz-hzi.de:10033/5940532019-08-30T11:33:01Zcom_10033_620656col_10033_620658
Sommer, Roman
Hauck, Dirk
Varrot, Annabelle
Wagner, Stefanie
Audfray, Aymeric
Prestel, Andreas
Möller, Heiko M.
Imberty, Anne
Titz, Alexander
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany.
Chemical Biology of Carbohydrates; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS); Universitätsstrasse 10 66123 Saarbrücken Germany
Chemical Biology of Carbohydrates; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS); Universitätsstrasse 10 66123 Saarbrücken Germany
Centre de Recherche sur les Macromolécules Végétales (CERMAV-UPR5301); CNRS and Université Grenoble Alpes, BP53; 38041 Grenoble cedex 9 France
Chemical Biology of Carbohydrates; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS); Universitätsstrasse 10 66123 Saarbrücken Germany
Centre de Recherche sur les Macromolécules Végétales (CERMAV-UPR5301); CNRS and Université Grenoble Alpes, BP53; 38041 Grenoble cedex 9 France
Department of Chemistry and Graduate School Chemical Biology; University of Konstanz; 78457 Konstanz Germany
Department of Chemistry and Graduate School Chemical Biology; University of Konstanz; 78457 Konstanz Germany
Centre de Recherche sur les Macromolécules Végétales (CERMAV-UPR5301); CNRS and Université Grenoble Alpes, BP53; 38041 Grenoble cedex 9 France
Chemical Biology of Carbohydrates; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS); Universitätsstrasse 10 66123 Saarbrücken Germany
2016-01-19T14:44:13Z
2016-01-19T14:44:13Z
2015-12
Cinnamide Derivatives of d -Mannose as Inhibitors of the Bacterial Virulence Factor LecB from Pseudomonas aeruginosa 2015, 4 (6):756 ChemistryOpen
21911363
10.1002/open.201500162
http://hdl.handle.net/10033/594053
ChemistryOpen
http://doi.wiley.com/10.1002/open.201500162
Cinnamide Derivatives of d -Mannose as Inhibitors of the Bacterial Virulence Factor LecB from Pseudomonas aeruginosa
Article2018-06-13T04:24:26Zoai:repository.helmholtz-hzi.de:10033/5957132019-08-30T11:37:23Zcom_10033_620656col_10033_620657
Reuter, Kerstin
Steinbach, Anke
Helms, Volkhard
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany.
2016-02-05T14:20:00Z
2016-02-05T14:20:00Z
2016
Interfering with Bacterial Quorum Sensing. 2016, 8:1-15 Perspect Medicin Chem
1177-391X
26819549
10.4137/PMC.S13209
http://hdl.handle.net/10033/595713
Perspectives in medicinal chemistry
Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery.
en
Interfering with Bacterial Quorum Sensing.
Article2018-06-13T01:32:19ZQuorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery.oai:repository.helmholtz-hzi.de:10033/5966492019-08-30T11:37:24Zcom_10033_620656col_10033_620657
Thomann, Andreas
Huch, Volker
Hartmann, Rolf W
Helmholtz Institute for Pharmaceutical Research Saarland (HIPS);Saarland University, Building A4.1, 66123 Saarbruecken, Germany.
2016-02-18T15:35:30Z
2016-02-18T15:35:30Z
2015-12-01
Crystal structure of 4-methyl-sulfanyl-2-(2H-tetra-zol-2-yl)pyrimidine. 2015, 71 (Pt 12):o1051-2 Acta Crystallogr E Crystallogr Commun
2056-9890
26870493
10.1107/S2056989015023634
http://hdl.handle.net/10033/596649
Acta crystallographica. Section E, Crystallographic communications
The title compound, C6H6N6S, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The conformation of the two mol-ecules differs slightly. While the tetra-zole ring is inclined to the pyrim-idene ring by 5.48 (7) and 4.24 (7)° in mol-ecules A and B, respectively, the N-C-S-C torsion angles of the thio-methyl groups differ by ca 180°. In the crystal, the A and B mol-ecules are linked via a C-H⋯N hydrogen bond. They stack along the b-axis direction forming columns within which there are weak π-π inter-actions present [shortest inter-centroid distance = 3.6933 (13) Å].
en
Crystal structure of 4-methyl-sulfanyl-2-(2H-tetra-zol-2-yl)pyrimidine.
Article2018-06-12T21:24:38ZThe title compound, C6H6N6S, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The conformation of the two mol-ecules differs slightly. While the tetra-zole ring is inclined to the pyrim-idene ring by 5.48 (7) and 4.24 (7)° in mol-ecules A and B, respectively, the N-C-S-C torsion angles of the thio-methyl groups differ by ca 180°. In the crystal, the A and B mol-ecules are linked via a C-H⋯N hydrogen bond. They stack along the b-axis direction forming columns within which there are weak π-π inter-actions present [shortest inter-centroid distance = 3.6933 (13) Å].oai:repository.helmholtz-hzi.de:10033/6043822019-08-30T11:35:39Zcom_10033_620656col_10033_620657
Krah, Simon
Schröter, Christian
Zielonka, Stefan
Empting, Martin
Valldorf, Bernhard
Kolmar, Harald
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Campus C2.3, D-66123 Saarbrücken, Germany.
2016-04-04T14:22:16Z
2016-04-04T14:22:16Z
2016-02
Single-domain antibodies for biomedical applications. 2016, 38 (1):21-8 Immunopharmacol Immunotoxicol
1532-2513
26551147
10.3109/08923973.2015.1102934
http://hdl.handle.net/10033/604382
Immunopharmacology and immunotoxicology
Single-domain antibodies are the smallest antigen-binding units of antibodies, consisting either only of one variable domain or one engineered constant domain that solely facilitates target binding. This class of antibody derivatives comprises naturally occurring variable domains derived from camelids and sharks as well as engineered human variable or constant antibody domains of the heavy or light chain. Because of their high affinity and specificity as well as stability, small size and benefit of multiple re-formatting opportunities, those molecules emerged as promising candidates for biomedical applications and some of these entities have already proven to be successful in clinical development.
en
Single-domain antibodies for biomedical applications.
Article2017-01-05T00:00:00ZSingle-domain antibodies are the smallest antigen-binding units of antibodies, consisting either only of one variable domain or one engineered constant domain that solely facilitates target binding. This class of antibody derivatives comprises naturally occurring variable domains derived from camelids and sharks as well as engineered human variable or constant antibody domains of the heavy or light chain. Because of their high affinity and specificity as well as stability, small size and benefit of multiple re-formatting opportunities, those molecules emerged as promising candidates for biomedical applications and some of these entities have already proven to be successful in clinical development.oai:repository.helmholtz-hzi.de:10033/6112232019-08-30T11:33:29Zcom_10033_620656col_10033_620658
Sommer, Roman
Wagner, Stefanie
Varrot, Annabelle
Nycholat, Corwin M.
Khaledi, Ariane
Häussler, Susanne
Paulson, James C.
Imberty, Anne
Titz, Alexander
2016-05-31T08:39:04Z
2016-05-31T08:39:04Z
2016
The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery 2016 Chem. Sci.
2041-6520
2041-6539
10.1039/C6SC00696E
http://hdl.handle.net/10033/611223
Chem. Sci.
http://xlink.rsc.org/?DOI=C6SC00696E
The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery
Article2018-06-12T16:46:00Zoai:repository.helmholtz-hzi.de:10033/6112272019-08-30T11:32:59Zcom_10033_620656col_10033_620657
Barthold, S.
Kletting, S.
Taffner, J.
de Souza Carvalho-Wodarz, C.
Lepeltier, E.
Loretz, B.
Lehr, Claus Michael
Helmholtz-Institut für pharmaceutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2016-05-31T12:16:24Z
2016-05-31T12:16:24Z
2016
Preparation of nanosized coacervates of positive and negative starch derivatives intended for pulmonary delivery of proteins 2016, 4 (13):2377 J. Mater. Chem. B
2050-750X
2050-7518
10.1039/C6TB00178E
http://hdl.handle.net/10033/611227
J. Mater. Chem. B
http://xlink.rsc.org/?DOI=C6TB00178E
Preparation of nanosized coacervates of positive and negative starch derivatives intended for pulmonary delivery of proteins
Article2018-06-12T17:28:50Zoai:repository.helmholtz-hzi.de:10033/6112592019-08-30T11:33:25Zcom_10033_620656col_10033_620658
Beshr, Ghamdan
Sommer, Roman
Hauck, Dirk
Siebert, David Chan Bodin
Hofmann, Anna
Imberty, Anne
Titz, Alexander
2016-05-31T14:35:19Z
2016-05-31T14:35:19Z
2016
Development of a competitive binding assay for the Burkholderia cenocepacia lectin BC2L-A and structure activity relationship of natural and synthetic inhibitors 2016, 7 (3):519 Med. Chem. Commun.
2040-2503
2040-2511
10.1039/C5MD00557D
http://hdl.handle.net/10033/611259
Med. Chem. Commun.
http://xlink.rsc.org/?DOI=C5MD00557D
Development of a competitive binding assay for the Burkholderia cenocepacia lectin BC2L-A and structure activity relationship of natural and synthetic inhibitors
Article2017-01-15T00:00:00Zoai:repository.helmholtz-hzi.de:10033/6156132019-08-30T11:30:58Zcom_10033_620656col_10033_620657
Gargano, Emanuele M
Allegretta, Giuseppe
Perspicace, Enrico
Carotti, Angelo
Van Koppen, Chris
Frotscher, Martin
Marchais-Oberwinkler, Sandrine
Hartmann, Rolf W
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland 9 University, 66123 Saarbrücken, Germany.
2016-07-06T09:39:32Z
2016-07-06T09:39:32Z
2015
17β-Hydroxysteroid Dehydrogenase Type 2 Inhibition: Discovery of Selective and Metabolically Stable Compounds Inhibiting Both the Human Enzyme and Its Murine Ortholog. 2015, 10 (7):e0134754 PLoS ONE
1932-6203
26230928
10.1371/journal.pone.0134754
http://hdl.handle.net/10033/615613
PloS one
Design and synthesis of a new class of inhibitors for the treatment of osteoporosis and its comparative h17β-HSD2 and m17β-HSD2 SAR study are described. 17a is the first compound to show strong inhibition of both h17β-HSD2 and m17β-HSD2, intracellular activity, metabolic stability, selectivity toward h17β-HSD1, m17β-HSD1 and estrogen receptors α and β as well as appropriate physicochemical properties for oral bioavailability. These properties make it eligible for pre-clinical animal studies, prior to human studies.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Animals
Cell Line, Tumor
Enzyme Inhibitors
Estradiol Dehydrogenases
Humans
Mice
Structure-Activity Relationship
17β-Hydroxysteroid Dehydrogenase Type 2 Inhibition: Discovery of Selective and Metabolically Stable Compounds Inhibiting Both the Human Enzyme and Its Murine Ortholog.
Article2018-06-13T19:42:16ZDesign and synthesis of a new class of inhibitors for the treatment of osteoporosis and its comparative h17β-HSD2 and m17β-HSD2 SAR study are described. 17a is the first compound to show strong inhibition of both h17β-HSD2 and m17β-HSD2, intracellular activity, metabolic stability, selectivity toward h17β-HSD1, m17β-HSD1 and estrogen receptors α and β as well as appropriate physicochemical properties for oral bioavailability. These properties make it eligible for pre-clinical animal studies, prior to human studies.oai:repository.helmholtz-hzi.de:10033/6159092019-08-30T11:30:58Zcom_10033_620656col_10033_620657
Elgaher, Walid A M
Sharma, Kamal K
Haupenthal, Jörg
Saladini, Francesco
Pires, Manuel
Real, Eleonore
Mély, Yves
Hartmann, Rolf W
Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany.
2016-07-11T14:26:33Z
2016-07-11T14:26:33Z
2016-07-07
Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors. 2016: J. Med. Chem.
1520-4804
27339173
10.1021/acs.jmedchem.6b00730
http://hdl.handle.net/10033/615909
Journal of medicinal chemistry
We are concerned with the development of novel anti-infectives with dual antibacterial and antiretroviral activities for MRSA/HIV-1 co-infection. To achieve this goal, we exploited for the first time the mechanistic function similarity between the bacterial RNA polymerase (RNAP) "switch region" and the viral non-nucleoside reverse transcriptase inhibitor (NNRTI) binding site. Starting from our previously discovered RNAP inhibitors, we managed to develop potent RT inhibitors effective against several resistant HIV-1 strains with maintained or enhanced RNAP inhibitory properties following a structure-based design approach. A quantitative structure-activity relationship (QSAR) analysis revealed distinct molecular features necessary for RT inhibition. Furthermore, mode of action (MoA) studies revealed that these compounds inhibit RT noncompetitively, through a new mechanism via closing of the RT clamp. In addition, the novel RNAP/RT inhibitors are characterized by a potent antibacterial activity against S. aureus and in cellulo antiretroviral activity against NNRTI-resistant strains. In HeLa and HEK 293 cells, the compounds showed only marginal cytotoxicity.
ENG
http://creativecommons.org/licenses/by-nc-sa/4.0/
Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors.
Article2017-07-15T00:00:00ZWe are concerned with the development of novel anti-infectives with dual antibacterial and antiretroviral activities for MRSA/HIV-1 co-infection. To achieve this goal, we exploited for the first time the mechanistic function similarity between the bacterial RNA polymerase (RNAP) "switch region" and the viral non-nucleoside reverse transcriptase inhibitor (NNRTI) binding site. Starting from our previously discovered RNAP inhibitors, we managed to develop potent RT inhibitors effective against several resistant HIV-1 strains with maintained or enhanced RNAP inhibitory properties following a structure-based design approach. A quantitative structure-activity relationship (QSAR) analysis revealed distinct molecular features necessary for RT inhibition. Furthermore, mode of action (MoA) studies revealed that these compounds inhibit RT noncompetitively, through a new mechanism via closing of the RT clamp. In addition, the novel RNAP/RT inhibitors are characterized by a potent antibacterial activity against S. aureus and in cellulo antiretroviral activity against NNRTI-resistant strains. In HeLa and HEK 293 cells, the compounds showed only marginal cytotoxicity.oai:repository.helmholtz-hzi.de:10033/6185992019-08-30T11:35:39Zcom_10033_620656col_10033_620657
Maurer, Christine K
Fruth, Martina
Empting, Martin
Avrutina, Olga
Hoßmann, Jörn
Nadmid, Suvd
Gorges, Jan
Herrmann, Jennifer
Kazmaier, Uli
Dersch, Petra
Müller, Rolf
Hartmann, Rolf W
German Centre for Infection Research (DZIF), PartnerSite Hannover-Braunschweig, 30625 Hannover, Germany.
2016-08-19T12:59:04Z
2016-08-19T12:59:04Z
2016-06
Discovery of the first small-molecule CsrA-RNA interaction inhibitors using biophysical screening technologies. 2016, 8 (9):931-47 Future Med Chem
1756-8927
27253623
10.4155/fmc-2016-0033
http://hdl.handle.net/10033/618599
Future medicinal chemistry
CsrA is a global post-transcriptional regulator protein affecting mRNA translation and/or stability. Widespread among bacteria, it is essential for their full virulence and thus represents a promising anti-infective drug target. Therefore, we aimed at the discovery of CsrA-RNA interaction inhibitors. Results & methodology: We followed two strategies: a screening of small molecules (A) and an RNA ligand-based approach (B). Using surface plasmon resonance-based binding and fluorescence polarization-based competition assays, (A) yielded seven small-molecule inhibitors, among them MM14 (IC50 of 4 µM). (B) resulted in RNA-based inhibitor GGARNA (IC50 of 113 µM).
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Discovery of the first small-molecule CsrA-RNA interaction inhibitors using biophysical screening technologies.
Article2017-06-15T00:00:00ZCsrA is a global post-transcriptional regulator protein affecting mRNA translation and/or stability. Widespread among bacteria, it is essential for their full virulence and thus represents a promising anti-infective drug target. Therefore, we aimed at the discovery of CsrA-RNA interaction inhibitors. Results & methodology: We followed two strategies: a screening of small molecules (A) and an RNA ligand-based approach (B). Using surface plasmon resonance-based binding and fluorescence polarization-based competition assays, (A) yielded seven small-molecule inhibitors, among them MM14 (IC50 of 4 µM). (B) resulted in RNA-based inhibitor GGARNA (IC50 of 113 µM).oai:repository.helmholtz-hzi.de:10033/6205942019-08-30T11:34:48Zcom_10033_620656col_10033_620657
Thomann, Andreas
Brengel, Christian
Börger, Carsten
Kail, Dagmar
Steinbach, Anke
Empting, Martin
Hartmann, Rolf W
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2016-11-25T11:41:20Z
2016-11-25T11:41:20Z
2016-11-21
Structure-Activity Relationships of 2-Sufonylpyrimidines as Quorum-Sensing Inhibitors to Tackle Biofilm Formation and eDNA Release of Pseudomonas aeruginosa. 2016, 11 (22):2522-2533 ChemMedChem
1860-7187
27731921
10.1002/cmdc.201600419
http://hdl.handle.net/10033/620594
ChemMedChem
Drug-resistant Pseudomonas aeruginosa (PA) strains are on the rise, making treatment with current antibiotics ineffective. Hence, circumventing resistance or restoring the activity of antibiotics by novel approaches is of high demand. Targeting the Pseudomonas quinolone signal quorum sensing (PQS-QS) system is an intriguing strategy to abolish PA pathogenicity without affecting the viability of the pathogen. Herein we report the structure-activity relationships of 2-sulfonylpyrimidines, which were previously identified as dual-target inhibitors of the PQS receptor PqsR and the PQS synthase PqsD. The SAR elucidation was guided by a combined approach using ligand efficiency and ligand lipophilicity efficiency to select the most promising compounds. In addition, the most effective inhibitors were rationally modified by the guidance of QSAR using Hansch analyses. Finally, these inhibitors showed the capacity to decrease biofilm mass and extracellular DNA, which are important determinants for antibiotic resistance.
ENG
http://creativecommons.org/licenses/by-nc-sa/4.0/
Structure-Activity Relationships of 2-Sufonylpyrimidines as Quorum-Sensing Inhibitors to Tackle Biofilm Formation and eDNA Release of Pseudomonas aeruginosa.
Article2017-10-12T00:00:00ZDrug-resistant Pseudomonas aeruginosa (PA) strains are on the rise, making treatment with current antibiotics ineffective. Hence, circumventing resistance or restoring the activity of antibiotics by novel approaches is of high demand. Targeting the Pseudomonas quinolone signal quorum sensing (PQS-QS) system is an intriguing strategy to abolish PA pathogenicity without affecting the viability of the pathogen. Herein we report the structure-activity relationships of 2-sulfonylpyrimidines, which were previously identified as dual-target inhibitors of the PQS receptor PqsR and the PQS synthase PqsD. The SAR elucidation was guided by a combined approach using ligand efficiency and ligand lipophilicity efficiency to select the most promising compounds. In addition, the most effective inhibitors were rationally modified by the guidance of QSAR using Hansch analyses. Finally, these inhibitors showed the capacity to decrease biofilm mass and extracellular DNA, which are important determinants for antibiotic resistance.oai:repository.helmholtz-hzi.de:10033/6208052019-08-30T11:36:32Zcom_10033_620656col_10033_620658
Sommer, Roman
Hauck, Dirk
Varrot, Annabelle
Imberty, Anne
Künzler, Markus
Titz, Alexander
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-02-03T11:38:00Z
2017-02-03T11:38:00Z
2016
O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside. 2016, 12:2828-2833 Beilstein J Org Chem
28144356
10.3762/bjoc.12.282
http://hdl.handle.net/10033/620805
Beilstein journal of organic chemistry
Selenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O-methylated selenoglycoside, specifically methyl 2-O-methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor. The synthetic route required a strategic revision and further optimization due to the intrinsic lability of alkyl selenoglycosides, in particular for the labile fucose. Here, we describe a successful synthetic access to methyl 2-O-methyl-L-selenofucopyranoside in 9 linear steps and 26% overall yield starting from allyl L-fucopyranoside.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside.
Article2018-06-12T22:56:38ZSelenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O-methylated selenoglycoside, specifically methyl 2-O-methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor. The synthetic route required a strategic revision and further optimization due to the intrinsic lability of alkyl selenoglycosides, in particular for the labile fucose. Here, we describe a successful synthetic access to methyl 2-O-methyl-L-selenofucopyranoside in 9 linear steps and 26% overall yield starting from allyl L-fucopyranoside.oai:repository.helmholtz-hzi.de:10033/6209172019-08-30T11:29:47Zcom_10033_620656col_10033_620657
Fazli, Mustafa
Rybtke, Morten
Steiner, Elisabeth
Weidel, Elisabeth
Berthelsen, Jens
Groizeleau, Julie
Bin, Wu
Zhi, Boo Zhao
Yaming, Zhang
Kaever, Volkhard
Givskov, Michael
Hartmann, Rolf W.
Eberl, Leo
Tolker-Nielsen, Tim
Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-05-12T14:47:05Z
2017-05-12T14:47:05Z
2017-04-16
Regulation of Burkholderia cenocepacia biofilm formation by RpoN and the c-di-GMP effector BerB. 2017 Microbiologyopen
2045-8827
28419759
10.1002/mbo3.480
http://hdl.handle.net/10033/620917
MicrobiologyOpen
Knowledge about the molecular mechanisms that are involved in the regulation of biofilm formation is essential for the development of biofilm-control measures. It is well established that the nucleotide second messenger cyclic diguanosine monophosphate (c-di-GMP) is a positive regulator of biofilm formation in many bacteria, but more knowledge about c-di-GMP effectors is needed. We provide evidence that c-di-GMP, the alternative sigma factor RpoN (σ54), and the enhancer-binding protein BerB play a role in biofilm formation of Burkholderia cenocepacia by regulating the production of a biofilm-stabilizing exopolysaccharide. Our findings suggest that BerB binds c-di-GMP, and activates RpoN-dependent transcription of the berA gene coding for a c-di-GMP-responsive transcriptional regulator. An increased level of the BerA protein in turn induces the production of biofilm-stabilizing exopolysaccharide in response to high c-di-GMP levels. Our findings imply that the production of biofilm exopolysaccharide in B. cenocepacia is regulated through a cascade involving two consecutive transcription events that are both activated by c-di-GMP. This type of regulation may allow tight control of the expenditure of cellular resources.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Regulation of Burkholderia cenocepacia biofilm formation by RpoN and the c-di-GMP effector BerB.
Article2018-06-12T23:13:31ZKnowledge about the molecular mechanisms that are involved in the regulation of biofilm formation is essential for the development of biofilm-control measures. It is well established that the nucleotide second messenger cyclic diguanosine monophosphate (c-di-GMP) is a positive regulator of biofilm formation in many bacteria, but more knowledge about c-di-GMP effectors is needed. We provide evidence that c-di-GMP, the alternative sigma factor RpoN (σ54), and the enhancer-binding protein BerB play a role in biofilm formation of Burkholderia cenocepacia by regulating the production of a biofilm-stabilizing exopolysaccharide. Our findings suggest that BerB binds c-di-GMP, and activates RpoN-dependent transcription of the berA gene coding for a c-di-GMP-responsive transcriptional regulator. An increased level of the BerA protein in turn induces the production of biofilm-stabilizing exopolysaccharide in response to high c-di-GMP levels. Our findings imply that the production of biofilm exopolysaccharide in B. cenocepacia is regulated through a cascade involving two consecutive transcription events that are both activated by c-di-GMP. This type of regulation may allow tight control of the expenditure of cellular resources.oai:repository.helmholtz-hzi.de:10033/6209342019-08-30T11:33:57Zcom_10033_620656col_10033_620658
Torge, Afra
Wagner, Stefanie
Chaves, Paula S
Oliveira, Edilene G
Guterres, Silvia S
Pohlmann, Adriana R
Titz, Alexander
Schneider, Marc
Beck, Ruy C R
Helmholtz Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-06-06T14:47:00Z
2017-06-06T14:47:00Z
2017-05-10
Ciprofloxacin-loaded lipid-core nanocapsules as mucus penetrating drug delivery system intended for the treatment of bacterial infections in cystic fibrosis. 2017, 527 (1-2):92-102 Int J Pharm
1873-3476
28499793
10.1016/j.ijpharm.2017.05.013
http://hdl.handle.net/10033/620934
International journal of pharmaceutics
Treatment of bacterial airway infections is essential for cystic fibrosis therapy. However, effectiveness of antibacterial treatment is limited as bacteria inside the mucus are protected from antibiotics and immune response. To overcome this biological barrier, ciprofloxacin was loaded into lipid-core nanocapsules (LNC) for high mucus permeability, sustained release and antibacterial activity. Ciprofloxacin-loaded LNC with a mean size of 180nm showed a by 50% increased drug permeation through mucus. In bacterial growth assays, the drug in the LNC had similar minimum inhibitory concentrations as the free drug in P. aeruginosa and S. aureus. Interestingly, formation of biofilm-like aggregates, which were observed for S. aureus treated with free ciprofloxacin, was avoided by exposure to LNC. With the combined advantages over the non-encapsulated drug, ciprofloxacin-loaded LNC represent a promising drug delivery system with the prospect of an improved antibiotic therapy in cystic fibrosis.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Ciprofloxacin-loaded lipid-core nanocapsules as mucus penetrating drug delivery system intended for the treatment of bacterial infections in cystic fibrosis.
Article2018-07-15T00:00:00ZTreatment of bacterial airway infections is essential for cystic fibrosis therapy. However, effectiveness of antibacterial treatment is limited as bacteria inside the mucus are protected from antibiotics and immune response. To overcome this biological barrier, ciprofloxacin was loaded into lipid-core nanocapsules (LNC) for high mucus permeability, sustained release and antibacterial activity. Ciprofloxacin-loaded LNC with a mean size of 180nm showed a by 50% increased drug permeation through mucus. In bacterial growth assays, the drug in the LNC had similar minimum inhibitory concentrations as the free drug in P. aeruginosa and S. aureus. Interestingly, formation of biofilm-like aggregates, which were observed for S. aureus treated with free ciprofloxacin, was avoided by exposure to LNC. With the combined advantages over the non-encapsulated drug, ciprofloxacin-loaded LNC represent a promising drug delivery system with the prospect of an improved antibiotic therapy in cystic fibrosis.oai:repository.helmholtz-hzi.de:10033/6209652019-08-30T11:34:22Zcom_10033_620656col_10033_620657
Allegretta, Giuseppe
Maurer, Christine K
Eberhard, Jens
Maura, Damien
Hartmann, Rolf W
Rahme, Laurence
Empting, Martin
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS),Saarland 9 University, 66123 Saarbrücken, Germany.
2017-06-21T08:51:17Z
2017-06-21T08:51:17Z
2017
In-depth Profiling of MvfR-Regulated Small Molecules in Pseudomonas aeruginosa after Quorum Sensing Inhibitor Treatment. 2017, 8:924 Front Microbiol
28596760
10.3389/fmicb.2017.00924
http://hdl.handle.net/10033/620965
Frontiers in microbiology
Pseudomonas aeruginosa is a Gram-negative bacterium, which causes opportunistic infections in immuno-compromised individuals. Due to its multiple resistances toward antibiotics, the development of new drugs is required. Interfering with Quorum Sensing (QS), a cell-to-cell communication system, has shown to be highly efficient in reducing P. aeruginosa pathogenicity. One of its QS systems employs Pseudomonas Quinolone Signal (PQS) and 4-hydroxy-2-heptylquinoline (HHQ) as signal molecules. Both activate the transcriptional regulator MvfR (Multiple Virulence Factor Regulator), also called PqsR, driving the production of QS molecules as well as toxins and biofilm formation. The aim of this work was to elucidate the effects of QS inhibitors (QSIs), such as MvfR antagonists and PqsBC inhibitors, on the biosynthesis of the MvfR-regulated small molecules 2'-aminoacetophenone (2-AA), dihydroxyquinoline (DHQ), HHQ, PQS, and 4-hydroxy-2-heptylquinoline-N-oxide (HQNO). The employed synthetic MvfR antagonist fully inhibited pqs small molecule formation showing expected sigmoidal dose-response curves for 2-AA, HQNO, HHQ and PQS. Surprisingly, DHQ levels were enhanced at lower antagonist concentrations followed by a full suppression at higher QSI amounts. This particular bi-phasic profile hinted at the accumulation of a biosynthetic intermediate resulting in the observed overproduction of the shunt product DHQ. Additionally, investigations on PqsBC inhibitors showed a reduction of MvfR natural ligands, while increased 2-AA, DHQ and HQNO levels compared to the untreated cells were detected. Moreover, PqsBC inhibitors did not show any significant effect in PA14 pqsC mutant demonstrating their target selectivity. As 2-AA is important for antibacterial tolerance, the QSIs were evaluated in their capability to attenuate persistence. Indeed, persister cells were reduced along with 2-AA inhibition resulting from MvfR antagonism, but not from PqsBC inhibition. In conclusion, antagonizing MvfR using a dosage capable of fully suppressing this QS system will lead to a favorable therapeutic outcome as DHQ overproduction is avoided and bacterial persistence is reduced.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
In-depth Profiling of MvfR-Regulated Small Molecules in Pseudomonas aeruginosa after Quorum Sensing Inhibitor Treatment.
Article2018-06-13T01:16:46ZPseudomonas aeruginosa is a Gram-negative bacterium, which causes opportunistic infections in immuno-compromised individuals. Due to its multiple resistances toward antibiotics, the development of new drugs is required. Interfering with Quorum Sensing (QS), a cell-to-cell communication system, has shown to be highly efficient in reducing P. aeruginosa pathogenicity. One of its QS systems employs Pseudomonas Quinolone Signal (PQS) and 4-hydroxy-2-heptylquinoline (HHQ) as signal molecules. Both activate the transcriptional regulator MvfR (Multiple Virulence Factor Regulator), also called PqsR, driving the production of QS molecules as well as toxins and biofilm formation. The aim of this work was to elucidate the effects of QS inhibitors (QSIs), such as MvfR antagonists and PqsBC inhibitors, on the biosynthesis of the MvfR-regulated small molecules 2'-aminoacetophenone (2-AA), dihydroxyquinoline (DHQ), HHQ, PQS, and 4-hydroxy-2-heptylquinoline-N-oxide (HQNO). The employed synthetic MvfR antagonist fully inhibited pqs small molecule formation showing expected sigmoidal dose-response curves for 2-AA, HQNO, HHQ and PQS. Surprisingly, DHQ levels were enhanced at lower antagonist concentrations followed by a full suppression at higher QSI amounts. This particular bi-phasic profile hinted at the accumulation of a biosynthetic intermediate resulting in the observed overproduction of the shunt product DHQ. Additionally, investigations on PqsBC inhibitors showed a reduction of MvfR natural ligands, while increased 2-AA, DHQ and HQNO levels compared to the untreated cells were detected. Moreover, PqsBC inhibitors did not show any significant effect in PA14 pqsC mutant demonstrating their target selectivity. As 2-AA is important for antibacterial tolerance, the QSIs were evaluated in their capability to attenuate persistence. Indeed, persister cells were reduced along with 2-AA inhibition resulting from MvfR antagonism, but not from PqsBC inhibition. In conclusion, antagonizing MvfR using a dosage capable of fully suppressing this QS system will lead to a favorable therapeutic outcome as DHQ overproduction is avoided and bacterial persistence is reduced.oai:repository.helmholtz-hzi.de:10033/6210192019-08-30T11:26:42Zcom_10033_620656col_10033_620657
Schmitt, Christian
Kail, Dagmar
Mariano, Marica
Empting, Martin
Weber, Nadja
Paul, Tamara
Hartmann, Rolf W.
Engel, Matthias
Helmholtz Institute für Pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-07-25T13:56:49Z
2017-07-25T13:56:49Z
2014
Design and synthesis of a library of lead-like 2,4-bisheterocyclic substituted thiophenes as selective Dyrk/Clk inhibitors. 2014, 9 (3):e87851 PLoS ONE
1932-6203
24676346
10.1371/journal.pone.0087851
http://hdl.handle.net/10033/621019
PloS one
The Dyrk family of protein kinases is implicated in the pathogenesis of several diseases, including cancer and neurodegeneration. Pharmacological inhibitors were mainly described for Dyrk1A so far, but in fewer cases for Dyrk1B, Dyrk2 or other isoforms. Herein, we report the development and optimization of 2,4-bisheterocyclic substituted thiophenes as a novel class of Dyrk inhibitors. The optimized hit compounds displayed favorable pharmacokinetic properties and high ligand efficiencies, and inhibited Dyrk1B in intact cells. In a larger selectivity screen, only Clk1 and Clk4 were identified as additional targets of compound 48, but no other kinases frequently reported as off-targets. Interestingly, Dyrk1A is implicated in the regulation of alternative splicing, a function shared with Clk1/Clk4; thus, some of the dual inhibitors might be useful as efficient splicing modulators. A further compound (29) inhibited Dyrk1A and 1B with an IC50 of 130 nM, showing a moderate selectivity over Dyrk2. Since penetration of the central nervous system (CNS) seems possible based on the physicochemical properties, this compound might serve as a lead for the development of potential therapeutic agents against glioblastoma. Furthermore, an inhibitor selective for Dyrk2 (24) was also identified, which might be are suitable as a pharmacological tool to dissect Dyrk2 isoform-mediated functions.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Animals
Caspase 3
Caspase 7
Cell Line, Tumor
Cricetinae
Drug Design
Drug Evaluation, Preclinical
Drug Screening Assays, Antitumor
Gene Expression Regulation
Humans
Inhibitory Concentration 50
Models, Molecular
Molecular Conformation
Molecular Structure
Protein Kinase Inhibitors
Protein-Serine-Threonine Kinases
Protein-Tyrosine Kinases
Reactive Oxygen Species
Recombinant Fusion Proteins
Small Molecule Libraries
Structure-Activity Relationship
Thiophenes
Design and synthesis of a library of lead-like 2,4-bisheterocyclic substituted thiophenes as selective Dyrk/Clk inhibitors.
Article2018-06-12T17:23:07ZThe Dyrk family of protein kinases is implicated in the pathogenesis of several diseases, including cancer and neurodegeneration. Pharmacological inhibitors were mainly described for Dyrk1A so far, but in fewer cases for Dyrk1B, Dyrk2 or other isoforms. Herein, we report the development and optimization of 2,4-bisheterocyclic substituted thiophenes as a novel class of Dyrk inhibitors. The optimized hit compounds displayed favorable pharmacokinetic properties and high ligand efficiencies, and inhibited Dyrk1B in intact cells. In a larger selectivity screen, only Clk1 and Clk4 were identified as additional targets of compound 48, but no other kinases frequently reported as off-targets. Interestingly, Dyrk1A is implicated in the regulation of alternative splicing, a function shared with Clk1/Clk4; thus, some of the dual inhibitors might be useful as efficient splicing modulators. A further compound (29) inhibited Dyrk1A and 1B with an IC50 of 130 nM, showing a moderate selectivity over Dyrk2. Since penetration of the central nervous system (CNS) seems possible based on the physicochemical properties, this compound might serve as a lead for the development of potential therapeutic agents against glioblastoma. Furthermore, an inhibitor selective for Dyrk2 (24) was also identified, which might be are suitable as a pharmacological tool to dissect Dyrk2 isoform-mediated functions.oai:repository.helmholtz-hzi.de:10033/6210892019-08-30T11:27:16Zcom_10033_620656col_10033_620657
Gobbi, Silvia
Hu, Qingzhong
Zimmer, Christina
Belluti, Federica
Rampa, Angela
Hartmann, Rolf W.
Bisi, Alessandra
HIPS, Helmholtz Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-09-04T13:33:12Z
2017-09-04T13:33:12Z
2017-08-02
Drifting of heme-coordinating group in imidazolylmethylxanthones leading to improved selective inhibition of CYP11B1. 2017, 139:60-67 Eur J Med Chem
1768-3254
28797884
10.1016/j.ejmech.2017.07.078
http://hdl.handle.net/10033/621089
European journal of medicinal chemistry
An abnormal increase in glucocorticoid levels is responsible for pathological disorders affecting different organs and systems, and the selective inhibition of appropriate steroidogenic enzymes represents a validated strategy to restore their physiological levels. In continuing our studies on CYP11B inhibitors, in this paper a small series of 6-substituted 3-imidazolylmethylxanthones was designed and synthesized, according to the data acquired from previously reported series of derivatives and from a purposely-performed docking study. The new compounds proved to be potent inhibitors of CYP11B isoforms, being effective on CYP11B1 in the low nanomolar range and improving selectivity with respect to CYP11B2, compared to previously reported related compounds. These data further confirmed that a suitable mutual arrangement of the imidazolylmethyl pharmacophore and a properly selected substituent on the xanthone core allows a fine tuning of the activity towards the different CYPs and further corroborate the role of the xanthone scaffold as a privileged structure in this field.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Drifting of heme-coordinating group in imidazolylmethylxanthones leading to improved selective inhibition of CYP11B1.
Article2018-10-20T00:00:00ZAn abnormal increase in glucocorticoid levels is responsible for pathological disorders affecting different organs and systems, and the selective inhibition of appropriate steroidogenic enzymes represents a validated strategy to restore their physiological levels. In continuing our studies on CYP11B inhibitors, in this paper a small series of 6-substituted 3-imidazolylmethylxanthones was designed and synthesized, according to the data acquired from previously reported series of derivatives and from a purposely-performed docking study. The new compounds proved to be potent inhibitors of CYP11B isoforms, being effective on CYP11B1 in the low nanomolar range and improving selectivity with respect to CYP11B2, compared to previously reported related compounds. These data further confirmed that a suitable mutual arrangement of the imidazolylmethyl pharmacophore and a properly selected substituent on the xanthone core allows a fine tuning of the activity towards the different CYPs and further corroborate the role of the xanthone scaffold as a privileged structure in this field.oai:repository.helmholtz-hzi.de:10033/6211122019-08-30T11:33:05Zcom_10033_620656col_10033_620657
Kamal, Ahmed A M
Petrera, Lucia
Eberhard, Jens
Hartmann, Rolf W.
Helmholtz-Institu für pharmazeutische Forschung Saarland,, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-09-18T12:58:35Z
2017-09-18T12:58:35Z
2017-05-31
Structure-functionality relationship and pharmacological profiles of Pseudomonas aeruginosa alkylquinolone quorum sensing modulators. 2017, 15 (21):4620-4630 Org. Biomol. Chem.
1477-0539
28513746
10.1039/c7ob00263g
http://hdl.handle.net/10033/621112
Organic & biomolecular chemistry
An important paradigm in anti-infective research is the antivirulence concept. Pathoblockers are compounds which disarm bacteria of their arsenal of virulence factors. PqsR is a transcriptional regulator controlling the production of such factors in Pseudomonas aeruginosa, most prominently pyocyanin. In this work, a series of tool compounds based on the structure of the natural ligand 2-heptyl-4-quinolone (HHQ) were used for probing the structure-functionality relationship. Four different profiles are identified namely agonists, antagonists, inverse agonists and biphasic modulators. Molecular docking studies revealed that each class of the PqsR modulators showed distinctive interactions in the PqsR binding domain. It was found that the substituents in position 3 of the quinolone core act as a switch between the different profiles, according to their ability to donate or accept a hydrogen bond, or form a hydrophobic interaction. Finally, it was shown that only inverse agonists were able to strongly inhibit pyocyanin production.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Structure-functionality relationship and pharmacological profiles of Pseudomonas aeruginosa alkylquinolone quorum sensing modulators.
Article2018-05-05T00:00:00ZAn important paradigm in anti-infective research is the antivirulence concept. Pathoblockers are compounds which disarm bacteria of their arsenal of virulence factors. PqsR is a transcriptional regulator controlling the production of such factors in Pseudomonas aeruginosa, most prominently pyocyanin. In this work, a series of tool compounds based on the structure of the natural ligand 2-heptyl-4-quinolone (HHQ) were used for probing the structure-functionality relationship. Four different profiles are identified namely agonists, antagonists, inverse agonists and biphasic modulators. Molecular docking studies revealed that each class of the PqsR modulators showed distinctive interactions in the PqsR binding domain. It was found that the substituents in position 3 of the quinolone core act as a switch between the different profiles, according to their ability to donate or accept a hydrogen bond, or form a hydrophobic interaction. Finally, it was shown that only inverse agonists were able to strongly inhibit pyocyanin production.oai:repository.helmholtz-hzi.de:10033/6211232019-08-30T11:31:49Zcom_10033_620656col_10033_620657
Könning, Doreen
Rhiel, Laura
Empting, Martin
Grzeschik, Julius
Sellmann, Carolin
Schröter, Christian
Zielonka, Stefan
Dickgießer, Stephan
Pirzer, Thomas
Yanakieva, Desislava
Becker, Stefan
Kolmar, Harald
Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-09-26T13:22:25Z
2017-09-26T13:22:25Z
2017-08-29
Semi-synthetic vNAR libraries screened against therapeutic antibodies primarily deliver anti-idiotypic binders. 2017, 7 (1):9676 Sci Rep
2045-2322
28852148
10.1038/s41598-017-10513-9
http://hdl.handle.net/10033/621123
Scientific reports
Anti-idiotypic binders which specifically recognize the variable region of monoclonal antibodies have proven to be robust tools for pharmacokinetic studies of antibody therapeutics and for the development of cancer vaccines. In the present investigation, we focused on the identification of anti-idiotypic, shark-derived IgNAR antibody variable domains (vNARs) targeting the therapeutic antibodies matuzumab and cetuximab for the purpose of developing specific capturing ligands. Using yeast surface display and semi-synthetic, CDR3-randomized libraries, we identified several highly specific binders targeting both therapeutic antibodies in their corresponding variable region, without applying any counter selections during screening. Importantly, anti-idiotypic vNAR binders were not cross-reactive towards cetuximab or matuzumab, respectively, and comprised good target recognition in the presence of human and mouse serum. When coupled to magnetic beads, anti-idiotypic vNAR variants could be used as efficient capturing tools. Moreover, a two-step procedure involving vNAR-functionalized beads was employed for the enrichment of potentially bispecific cetuximab × matuzumab antibody constructs. In conclusion, semi-synthetic and CDR3-randomized vNAR libraries in combination with yeast display enable the fast and facile identification of anti-idiotypic vNAR domains targeting monoclonal antibodies primarily in an anti-idiotypic manner.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Semi-synthetic vNAR libraries screened against therapeutic antibodies primarily deliver anti-idiotypic binders.
Article2018-06-13T02:43:44ZAnti-idiotypic binders which specifically recognize the variable region of monoclonal antibodies have proven to be robust tools for pharmacokinetic studies of antibody therapeutics and for the development of cancer vaccines. In the present investigation, we focused on the identification of anti-idiotypic, shark-derived IgNAR antibody variable domains (vNARs) targeting the therapeutic antibodies matuzumab and cetuximab for the purpose of developing specific capturing ligands. Using yeast surface display and semi-synthetic, CDR3-randomized libraries, we identified several highly specific binders targeting both therapeutic antibodies in their corresponding variable region, without applying any counter selections during screening. Importantly, anti-idiotypic vNAR binders were not cross-reactive towards cetuximab or matuzumab, respectively, and comprised good target recognition in the presence of human and mouse serum. When coupled to magnetic beads, anti-idiotypic vNAR variants could be used as efficient capturing tools. Moreover, a two-step procedure involving vNAR-functionalized beads was employed for the enrichment of potentially bispecific cetuximab × matuzumab antibody constructs. In conclusion, semi-synthetic and CDR3-randomized vNAR libraries in combination with yeast display enable the fast and facile identification of anti-idiotypic vNAR domains targeting monoclonal antibodies primarily in an anti-idiotypic manner.oai:repository.helmholtz-hzi.de:10033/6211472019-08-30T11:31:23Zcom_10033_620656col_10033_620657
Liu, Yun
Stuart, Marc C A
Witte, Martin D
Buhler, Eric
Hirsch, Anna K H
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Universitycampus E8.1, 66123 Saarbrücken, Germany.
2017-11-01T08:31:27Z
2017-11-01T08:31:27Z
2017-10-05
Saccharide-Containing Dynamic Proteoids. 2017 Chemistry
1521-3765
28981987
10.1002/chem.201703584
http://hdl.handle.net/10033/621147
Chemistry (Weinheim an der Bergstrasse, Germany)
Dynamic proteoids are dynamic covalent analogues of proteins, which can be used as new adaptive biomaterials. We designed and synthesized a range of sugar-containing dynamic proteoid biodynamers based on the polycondensation of different types of amino acid and dipeptide hydrazides with a biological aliphatic dialdehyde and a nonbiological aromatic dialdehyde. By using the saccharide-based dialdehyde, the biocompatibility of biodynamers should be enhanced compared to previously reported biodynamers.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Saccharide-Containing Dynamic Proteoids.
Article2018-06-13T00:01:46ZDynamic proteoids are dynamic covalent analogues of proteins, which can be used as new adaptive biomaterials. We designed and synthesized a range of sugar-containing dynamic proteoid biodynamers based on the polycondensation of different types of amino acid and dipeptide hydrazides with a biological aliphatic dialdehyde and a nonbiological aromatic dialdehyde. By using the saccharide-based dialdehyde, the biocompatibility of biodynamers should be enhanced compared to previously reported biodynamers.oai:repository.helmholtz-hzi.de:10033/6211482019-08-30T11:33:29Zcom_10033_620656col_10033_620658
Beshr, Ghamdan
Sikandar, Asfandyar
Jemiller, Eva-Maria
Klymiuk, Nikolai
Hauck, Dirk
Wagner, Stefanie
Wolf, Eckhard
Koehnke, Jesko
Titz, Alexander
Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Universitycampus E8.1, 66123 Saarbrücken, Germany.
2017-11-01T10:37:09Z
2017-11-01T10:37:09Z
2017-09-28
Photorhabdus luminescens lectin A (PllA) - a new probe for detecting α-galactoside-terminating glycoconjugates. 2017 J. Biol. Chem.
1083-351X
28972138
10.1074/jbc.M117.812792
http://hdl.handle.net/10033/621148
The Journal of biological chemistry
Lectins play important roles in infections by pathogenic bacteria, for example, in host colonization, persistence and biofilm formation. The Gram-negative entomopathogenic bacterium Photorhabdus luminescens symbiotically lives in insect-infecting Heterorhabditis nematodes and kills the insect host upon invasion by the nematode. The P. luminescens genome harbors the gene plu2096 coding for a novel lectin that we named PllA. We analyzed the binding properties of purified PllA with a glycan array and a binding assay in solution. Both assays revealed a strict specificity of PllA for alpha-galactoside-terminating glycoconjugates. The crystal structures of apo PllA and complexes with three different ligands revealed the molecular basis for the strict specificity of this lectin. Furthermore, we found that a 90 degree twist in subunit orientation leads to a peculiar quaternary structure compared with that of its ortholog LecA from Pseudomonas aeruginosa. We also investigated the utility of PllA as a probe for detecting alpha-galactosides. The alpha-Gal epitope is present on wild-type pig cells and the main reason for hyperacute organ rejection in pig to primate xenotransplantation. We noted that PllA specifically recognizes this epitope on the glycan array and demonstrated that PllA can be used as a fluorescent probe to detect this epitope on primary porcine cells in vitro. In summary, our biochemical and structural analyses of the P. luminescens lectin PllA have disclosed the structural basis for PllAs high specificity for alpha-galactoside-containing ligands, and we show that PllA can be used to visualize alpha-Gal epitope on porcine tissues.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Photorhabdus luminescens lectin A (PllA) - a new probe for detecting α-galactoside-terminating glycoconjugates.
ArticleLectins play important roles in infections by pathogenic bacteria, for example, in host colonization, persistence and biofilm formation. The Gram-negative entomopathogenic bacterium Photorhabdus luminescens symbiotically lives in insect-infecting Heterorhabditis nematodes and kills the insect host upon invasion by the nematode. The P. luminescens genome harbors the gene plu2096 coding for a novel lectin that we named PllA. We analyzed the binding properties of purified PllA with a glycan array and a binding assay in solution. Both assays revealed a strict specificity of PllA for alpha-galactoside-terminating glycoconjugates. The crystal structures of apo PllA and complexes with three different ligands revealed the molecular basis for the strict specificity of this lectin. Furthermore, we found that a 90 degree twist in subunit orientation leads to a peculiar quaternary structure compared with that of its ortholog LecA from Pseudomonas aeruginosa. We also investigated the utility of PllA as a probe for detecting alpha-galactosides. The alpha-Gal epitope is present on wild-type pig cells and the main reason for hyperacute organ rejection in pig to primate xenotransplantation. We noted that PllA specifically recognizes this epitope on the glycan array and demonstrated that PllA can be used as a fluorescent probe to detect this epitope on primary porcine cells in vitro. In summary, our biochemical and structural analyses of the P. luminescens lectin PllA have disclosed the structural basis for PllAs high specificity for alpha-galactoside-containing ligands, and we show that PllA can be used to visualize alpha-Gal epitope on porcine tissues.oai:repository.helmholtz-hzi.de:10033/6211532019-08-30T11:31:23Zcom_10033_620656col_10033_620657
Schönauer, Esther
Kany, Andreas M
Haupenthal, Jörg
Hüsecken, Kristina
Hoppe, Isabel J
Voos, Katrin
Yahiaoui, Samir
Elsässer, Brigitta
Ducho, Christian
Brandstetter, Hans
Hartmann, Rolf W.
Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-11-02T10:29:34Z
2017-11-02T10:29:34Z
2017-09-13
Discovery of a Potent Inhibitor Class with High Selectivity toward Clostridial Collagenases. 2017, 139 (36):12696-12703 J. Am. Chem. Soc.
1520-5126
28820255
10.1021/jacs.7b06935
http://hdl.handle.net/10033/621153
Journal of the American Chemical Society
Secreted virulence factors like bacterial collagenases are conceptually attractive targets for fighting microbial infections. However, previous attempts to develop potent compounds against these metalloproteases failed to achieve selectivity against human matrix metalloproteinases (MMPs). Using a surface plasmon resonance-based screening complemented with enzyme inhibition assays, we discovered an N-aryl mercaptoacetamide-based inhibitor scaffold that showed sub-micromolar affinities toward collagenase H (ColH) from the human pathogen Clostridium histolyticum. Moreover, these inhibitors also efficiently blocked the homologous bacterial collagenases, ColG from C. histolyticum, ColT from C. tetani, and ColQ1 from the Bacillus cereus strain Q1, while showing negligible activity toward human MMPs-1, -2, -3, -7, -8, and -14. The most active compound displayed a more than 1000-fold selectivity over human MMPs. This selectivity can be rationalized by the crystal structure of ColH with this compound, revealing a distinct non-primed binding mode to the active site. The non-primed binding mode presented here paves the way for the development of selective broad-spectrum bacterial collagenase inhibitors with potential therapeutic application in humans.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Discovery of a Potent Inhibitor Class with High Selectivity toward Clostridial Collagenases.
Article2018-06-13T01:19:46ZSecreted virulence factors like bacterial collagenases are conceptually attractive targets for fighting microbial infections. However, previous attempts to develop potent compounds against these metalloproteases failed to achieve selectivity against human matrix metalloproteinases (MMPs). Using a surface plasmon resonance-based screening complemented with enzyme inhibition assays, we discovered an N-aryl mercaptoacetamide-based inhibitor scaffold that showed sub-micromolar affinities toward collagenase H (ColH) from the human pathogen Clostridium histolyticum. Moreover, these inhibitors also efficiently blocked the homologous bacterial collagenases, ColG from C. histolyticum, ColT from C. tetani, and ColQ1 from the Bacillus cereus strain Q1, while showing negligible activity toward human MMPs-1, -2, -3, -7, -8, and -14. The most active compound displayed a more than 1000-fold selectivity over human MMPs. This selectivity can be rationalized by the crystal structure of ColH with this compound, revealing a distinct non-primed binding mode to the active site. The non-primed binding mode presented here paves the way for the development of selective broad-spectrum bacterial collagenase inhibitors with potential therapeutic application in humans.oai:repository.helmholtz-hzi.de:10033/6211712019-08-30T11:33:05Zcom_10033_620656col_10033_620657
Monjas, Leticia
Swier, Lotteke J Y M
Setyawati, Inda
Slotboom, Dirk J
Hirsch, Anna K H
Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus E9.1, 66123 Saarbrücken, Germany.
2017-11-08T13:08:39Z
2017-11-08T13:08:39Z
2017-10-20
Dynamic Combinatorial Chemistry to Identify Binders of ThiT, an S-Component of the Energy-Coupling Factor Transporter for Thiamine. 2017, 12 (20):1693-1696 ChemMedChem
1860-7187
28960943
10.1002/cmdc.201700440
http://hdl.handle.net/10033/621171
ChemMedChem
We applied dynamic combinatorial chemistry (DCC) to identify ligands of ThiT, the S-component of the energy-coupling factor (ECF) transporter for thiamine in Lactococcus lactis. We used a pre-equilibrated dynamic combinatorial library (DCL) and saturation-transfer difference (STD) NMR spectroscopy to identify ligands of ThiT. This is the first report in which DCC is used for fragment growing to an ill-defined pocket, and one of the first reports for its application with an integral membrane protein as target.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
ATP-Binding Cassette Transporters
Bacterial Proteins
Biological Transport
Carrier Proteins
Combinatorial Chemistry Techniques
Drug Design
Lactococcus lactis
Models, Molecular
Molecular Structure
Protein Subunits
Small Molecule Libraries
Thiamine
Dynamic Combinatorial Chemistry to Identify Binders of ThiT, an S-Component of the Energy-Coupling Factor Transporter for Thiamine.
Article2018-06-13T14:07:13ZWe applied dynamic combinatorial chemistry (DCC) to identify ligands of ThiT, the S-component of the energy-coupling factor (ECF) transporter for thiamine in Lactococcus lactis. We used a pre-equilibrated dynamic combinatorial library (DCL) and saturation-transfer difference (STD) NMR spectroscopy to identify ligands of ThiT. This is the first report in which DCC is used for fragment growing to an ill-defined pocket, and one of the first reports for its application with an integral membrane protein as target.oai:repository.helmholtz-hzi.de:10033/6212122019-08-30T11:34:22Zcom_10033_620656com_10033_620618col_10033_620658col_10033_620619
Wagner, Stefanie
Hauck, Dirk
Hoffmann, Michael
Sommer, Roman
Joachim, Ines
Müller, Rolf
Imberty, Anne
Varrot, Annabelle
Titz, Alexander
HIPS, Helmholtz-Institut für pharmazeutische Forchung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2017-12-20T10:44:14Z
2017-12-20T10:44:14Z
2017-09-28
Covalent Lectin Inhibition and Application in Bacterial Biofilm Imaging. 2017 Angew. Chem. Int. Ed. Engl.
1521-3773
28960731
10.1002/anie.201709368
http://hdl.handle.net/10033/621212
Angewandte Chemie (International ed. in English)
Biofilm formation by pathogenic bacteria is a hallmark of chronic infections. In many cases, lectins play key roles in establishing biofilms. The pathogen Pseudomonas aeruginosa often exhibiting various drug resistances employs its lectins LecA and LecB as virulence factors and biofilm building blocks. Therefore, inhibition of the function of these proteins is thought to have potential in developing "pathoblockers" preventing biofilm formation and virulence. A covalent lectin inhibitor specific to a carbohydrate binding site is described for the first time. Its application in the LecA-specific in vitro imaging of biofilms formed by P. aeruginosa is also reported.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Covalent Lectin Inhibition and Application in Bacterial Biofilm Imaging.
ArticleBiofilm formation by pathogenic bacteria is a hallmark of chronic infections. In many cases, lectins play key roles in establishing biofilms. The pathogen Pseudomonas aeruginosa often exhibiting various drug resistances employs its lectins LecA and LecB as virulence factors and biofilm building blocks. Therefore, inhibition of the function of these proteins is thought to have potential in developing "pathoblockers" preventing biofilm formation and virulence. A covalent lectin inhibitor specific to a carbohydrate binding site is described for the first time. Its application in the LecA-specific in vitro imaging of biofilms formed by P. aeruginosa is also reported.oai:repository.helmholtz-hzi.de:10033/6212352019-08-30T11:32:16Zcom_10033_620656col_10033_620657
Marcozzi, Alessio
Masini, Tiziana
Zhu, Di
Pesce, Diego
Illarionov, Boris
Fischer, Markus
Herrmann, Andreas
Hirsch, Anna Katharina Herta
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2018-01-17T11:44:13Z
2018-01-17T11:44:13Z
2018-01-04
Phage Display on the Anti-infective Target 1-Deoxy-d-xylulose-5-phosphate Synthase Leads to an Acceptor-Substrate Competitive Peptidic Inhibitor. 2018, 19 (1):58-65 Chembiochem
1439-7633
29119720
10.1002/cbic.201700402
http://hdl.handle.net/10033/621235
Chembiochem : a European journal of chemical biology
Enzymes of the 2-C-methyl-d-erythritol-4-phosphate pathway for the biosynthesis of isoprenoid precursors are validated drug targets. By performing phage display on 1-deoxy-d-xylulose-5-phosphate synthase (DXS), which catalyzes the first step of this pathway, we discovered several peptide hits and recognized false-positive hits. The enriched peptide binder P12 emerged as a substrate (d-glyceraldehyde-3-phosphate)-competitive inhibitor of Deinococcus radiodurans DXS. The results indicate possible overlap of the cofactor- and acceptor-substrate-binding pockets and provide inspiration for the design of inhibitors of DXS with a unique and novel mechanism of inhibition.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Phage Display on the Anti-infective Target 1-Deoxy-d-xylulose-5-phosphate Synthase Leads to an Acceptor-Substrate Competitive Peptidic Inhibitor.
Article2018-06-12T18:08:03ZEnzymes of the 2-C-methyl-d-erythritol-4-phosphate pathway for the biosynthesis of isoprenoid precursors are validated drug targets. By performing phage display on 1-deoxy-d-xylulose-5-phosphate synthase (DXS), which catalyzes the first step of this pathway, we discovered several peptide hits and recognized false-positive hits. The enriched peptide binder P12 emerged as a substrate (d-glyceraldehyde-3-phosphate)-competitive inhibitor of Deinococcus radiodurans DXS. The results indicate possible overlap of the cofactor- and acceptor-substrate-binding pockets and provide inspiration for the design of inhibitors of DXS with a unique and novel mechanism of inhibition.oai:repository.helmholtz-hzi.de:10033/6212642019-08-30T11:31:46Zcom_10033_620656col_10033_620658
Calvert, Matthew B
Mayer, Christoph
Titz, Alexander
Helmholtz Institut für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2018-02-06T14:41:09Z
2018-02-06T14:41:09Z
2017-12-11
An efficient synthesis of 1,6-anhydro- N -acetylmuramic acid from N -acetylglucosamine 2017, 13:2631 Beilstein Journal of Organic Chemistry
1860-5397
30018663
10.3762/bjoc.13.261
http://hdl.handle.net/10033/621264
Beilstein Journal of Organic Chemistry
http://www.beilstein-journals.org/bjoc/content/13/1/261
http://creativecommons.org/licenses/by-nc-sa/4.0/
An efficient synthesis of 1,6-anhydro- N -acetylmuramic acid from N -acetylglucosamine
Article2018-06-12T23:36:38Zoai:repository.helmholtz-hzi.de:10033/6212922019-08-30T11:36:33Zcom_10033_620656col_10033_620658
Hottmann, Isabel
Mayer, Valentina M T
Tomek, Markus B
Friedrich, Valentin
Calvert, Matthew B
Titz, Alexander
Schäffer, Christina
Mayer, Christoph
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-02-21T14:22:42Z
2018-02-21T14:22:42Z
2018
N-Acetylmuramic Acid (MurNAc) Auxotrophy of the Oral PathogenTannerella forsythia: Characterization of a MurNAc Kinase and Analysis of Its Role in Cell Wall Metabolism. 2018, 9:19 Front Microbiol
1664-302X
29434575
10.3389/fmicb.2018.00019
http://hdl.handle.net/10033/621292
Frontiers in microbiology
Tannerella forsythia is an anaerobic, Gram-negative oral pathogen that thrives in multispecies gingival biofilms associated with periodontitis. The bacterium is auxotrophic for the commonly essential bacterial cell wall sugarN-acetylmuramic acid (MurNAc) and, thus, strictly depends on an exogenous supply of MurNAc for growth and maintenance of cell morphology. A MurNAc transporter (Tf_MurT; Tanf_08375) and an ortholog of theEscherichia colietherase MurQ (Tf_MurQ; Tanf_08385) converting MurNAc-6-phosphate to GlcNAc-6-phosphate were recently described forT. forsythia.In between the respective genes on theT. forsythiagenome, a putative kinase gene is located. In this study, the putative kinase (Tf_MurK; Tanf_08380) was produced as a recombinant protein and biochemically characterized. Kinetic studies revealed Tf_MurK to be a 6-kinase with stringent substrate specificity for MurNAc exhibiting a 6 × 104-fold higher catalytic efficiency (kcat/Km) for MurNAc than forN-acetylglucosamine (GlcNAc) withkcatvalues of 10.5 s-1and 0.1 s-1andKmvalues of 200 μM and 116 mM, respectively. The enzyme kinetic data suggest that Tf_MurK is subject to substrate inhibition (Ki[S]= 4.2 mM). To assess the role of Tf_MurK in the cell wall metabolism ofT. forsythia, a kinase deletion mutant (ΔTf_murK::erm) was constructed. This mutant accumulated MurNAc intracellularly in the exponential phase, indicating the capability to take up MurNAc, but inability to catabolize MurNAc. In the stationary phase, the MurNAc level was reduced in the mutant, while the level of the peptidoglycan precursor UDP-MurNAc-pentapeptide was highly elevated. Further, according to scanning electron microscopy evidence, theΔTf_murK::ermmutant was more tolerant toward low MurNAc concentration in the medium (below 0.5 μg/ml) before transition from healthy, rod-shaped to fusiform cells occurred, while the parent strain required > 1 μg/ml MurNAc for optimal growth. These data reveal thatT. forsythiareadily catabolizes exogenous MurNAc but simultaneously channels a proportion of the sugar into peptidoglycan biosynthesis. Deletion ofTf_murKblocks MurNAc catabolism and allows the direction of MurNAc solely to peptidoglycan biosynthesis, resulting in a growth advantage in MurNAc-depleted medium. This work increases our understanding of theT. forsythiacell wall metabolism and may pave new routes for lead finding in the treatment of periodontitis.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
N-Acetylmuramic Acid (MurNAc) Auxotrophy of the Oral PathogenTannerella forsythia: Characterization of a MurNAc Kinase and Analysis of Its Role in Cell Wall Metabolism.
Article2018-06-13T05:40:56ZTannerella forsythia
is an anaerobic, Gram-negative oral pathogen that thrives in multispecies gingival biofilms associated with periodontitis. The bacterium is auxotrophic for the commonly essential bacterial cell wall sugarN-acetylmuramic acid (MurNAc) and, thus, strictly depends on an exogenous supply of MurNAc for growth and maintenance of cell morphology. A MurNAc transporter (Tf_MurT; Tanf_08375) and an ortholog of theEscherichia colietherase MurQ (Tf_MurQ; Tanf_08385) converting MurNAc-6-phosphate to GlcNAc-6-phosphate were recently described forT. forsythia.In between the respective genes on theT. forsythiagenome, a putative kinase gene is located. In this study, the putative kinase (Tf_MurK; Tanf_08380) was produced as a recombinant protein and biochemically characterized. Kinetic studies revealed Tf_MurK to be a 6-kinase with stringent substrate specificity for MurNAc exhibiting a 6 × 104-fold higher catalytic efficiency (kcat/Km) for MurNAc than forN-acetylglucosamine (GlcNAc) withkcatvalues of 10.5 s-1and 0.1 s-1andKmvalues of 200 μM and 116 mM, respectively. The enzyme kinetic data suggest that Tf_MurK is subject to substrate inhibition (Ki[S]= 4.2 mM). To assess the role of Tf_MurK in the cell wall metabolism ofT. forsythia, a kinase deletion mutant (ΔTf_murK::erm) was constructed. This mutant accumulated MurNAc intracellularly in the exponential phase, indicating the capability to take up MurNAc, but inability to catabolize MurNAc. In the stationary phase, the MurNAc level was reduced in the mutant, while the level of the peptidoglycan precursor UDP-MurNAc-pentapeptide was highly elevated. Further, according to scanning electron microscopy evidence, theΔTf_murK::ermmutant was more tolerant toward low MurNAc concentration in the medium (below 0.5 μg/ml) before transition from healthy, rod-shaped to fusiform cells occurred, while the parent strain required > 1 μg/ml MurNAc for optimal growth. These data reveal thatT. forsythiareadily catabolizes exogenous MurNAc but simultaneously channels a proportion of the sugar into peptidoglycan biosynthesis. Deletion ofTf_murKblocks MurNAc catabolism and allows the direction of MurNAc solely to peptidoglycan biosynthesis, resulting in a growth advantage in MurNAc-depleted medium. This work increases our understanding of theT. forsythiacell wall metabolism and may pave new routes for lead finding in the treatment of periodontitis.oai:repository.helmholtz-hzi.de:10033/6213382019-08-30T11:33:57Zcom_10033_338554com_10033_620656com_10033_311308col_10033_621050col_10033_620721col_10033_620657
Bussey, Kendra A
Lau, Ulrike
Schumann, Sophie
Gallo, Antonio
Osbelt, Lisa
Stempel, Markus
Arnold, Christine
Wissing, Josef
Gad, Hans Henrik
Hartmann, Rune
Brune, Wolfram
Jänsch, Lothar
Whitehouse, Adrian
Brinkmann, Melanie M
Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany.
2018-04-06T11:02:25Z
2018-04-06T11:02:25Z
2018-03
The interferon-stimulated gene product oligoadenylate synthetase-like protein enhances replication of Kaposi's sarcoma-associated herpesvirus (KSHV) and interacts with the KSHV ORF20 protein. 2018, 14 (3):e1006937 PLoS Pathog.
1553-7374
29499066
10.1371/journal.ppat.1006937
http://hdl.handle.net/10033/621338
PLoS pathogens
Kaposi's sarcoma-associated herpesvirus (KSHV) is one of the few oncogenic human viruses known to date. Its large genome encodes more than 85 proteins and includes both unique viral proteins as well as proteins conserved amongst herpesviruses. KSHV ORF20 is a member of the herpesviral core UL24 family, but the function of ORF20 and its role in the viral life cycle is not well understood. ORF20 encodes three largely uncharacterized isoforms, which we found were localized predominantly in the nuclei and nucleoli. Quantitative affinity purification coupled to mass spectrometry (q-AP-MS) identified numerous specific interacting partners of ORF20, including ribosomal proteins and the interferon-stimulated gene product (ISG) oligoadenylate synthetase-like protein (OASL). Both endogenous and transiently transfected OASL co-immunoprecipitated with ORF20, and this interaction was conserved among all ORF20 isoforms and multiple ORF20 homologs of the UL24 family in other herpesviruses. Characterization of OASL interacting partners by q-AP-MS identified a very similar interactome to that of ORF20. Both ORF20 and OASL copurified with 40S and 60S ribosomal subunits, and when they were co-expressed, they associated with polysomes. Although ORF20 did not have a global effect on translation, ORF20 enhanced RIG-I induced expression of endogenous OASL in an IRF3-dependent but IFNAR-independent manner. OASL has been characterized as an ISG with antiviral activity against some viruses, but its role for gammaherpesviruses was unknown. We show that OASL and ORF20 mRNA expression were induced early after reactivation of latently infected HuARLT-rKSHV.219 cells. Intriguingly, we found that OASL enhanced infection of KSHV. During infection with a KSHV ORF20stop mutant, however, OASL-dependent enhancement of infectivity was lost. Our data have characterized the interaction of ORF20 with OASL and suggest ORF20 usurps the function of OASL to benefit KSHV infection.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
The interferon-stimulated gene product oligoadenylate synthetase-like protein enhances replication of Kaposi's sarcoma-associated herpesvirus (KSHV) and interacts with the KSHV ORF20 protein.
Article2018-06-12T16:56:58ZKaposi's sarcoma-associated herpesvirus (KSHV) is one of the few oncogenic human viruses known to date. Its large genome encodes more than 85 proteins and includes both unique viral proteins as well as proteins conserved amongst herpesviruses. KSHV ORF20 is a member of the herpesviral core UL24 family, but the function of ORF20 and its role in the viral life cycle is not well understood. ORF20 encodes three largely uncharacterized isoforms, which we found were localized predominantly in the nuclei and nucleoli. Quantitative affinity purification coupled to mass spectrometry (q-AP-MS) identified numerous specific interacting partners of ORF20, including ribosomal proteins and the interferon-stimulated gene product (ISG) oligoadenylate synthetase-like protein (OASL). Both endogenous and transiently transfected OASL co-immunoprecipitated with ORF20, and this interaction was conserved among all ORF20 isoforms and multiple ORF20 homologs of the UL24 family in other herpesviruses. Characterization of OASL interacting partners by q-AP-MS identified a very similar interactome to that of ORF20. Both ORF20 and OASL copurified with 40S and 60S ribosomal subunits, and when they were co-expressed, they associated with polysomes. Although ORF20 did not have a global effect on translation, ORF20 enhanced RIG-I induced expression of endogenous OASL in an IRF3-dependent but IFNAR-independent manner. OASL has been characterized as an ISG with antiviral activity against some viruses, but its role for gammaherpesviruses was unknown. We show that OASL and ORF20 mRNA expression were induced early after reactivation of latently infected HuARLT-rKSHV.219 cells. Intriguingly, we found that OASL enhanced infection of KSHV. During infection with a KSHV ORF20stop mutant, however, OASL-dependent enhancement of infectivity was lost. Our data have characterized the interaction of ORF20 with OASL and suggest ORF20 usurps the function of OASL to benefit KSHV infection.oai:repository.helmholtz-hzi.de:10033/6213662019-08-30T11:25:11Zcom_10033_620656col_10033_620658
Sommer, Roman
Makshakova, Olga N
Wohlschlager, Therese
Hutin, Stephanie
Marsh, May
Titz, Alexander
Künzler, Markus
Varrot, Annabelle
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-05-07T12:38:06Z
2018-05-07T12:38:06Z
2018-03-06
Crystal Structures of Fungal Tectonin in Complex with O-Methylated Glycans Suggest Key Role in Innate Immune Defense. 2018, 26 (3):391-402.e4 Structure
1878-4186
29398527
10.1016/j.str.2018.01.003
http://hdl.handle.net/10033/621366
Structure (London, England : 1993)
Innate immunity is the first line of defense against pathogens and predators. To initiate a response, it relies on the detection of invaders, where lectin-carbohydrate interactions play a major role. O-Methylated glycans were previously identified as non-self epitopes and conserved targets for defense effector proteins belonging to the tectonin superfamily. Here, we present two crystal structures of Tectonin 2 from the mushroom Laccaria bicolor in complex with methylated ligands, unraveling the molecular basis for this original specificity. Furthermore, they revealed the formation of a ball-shaped tetramer with 24 binding sites distributed at its surface, resembling a small virus capsid. Based on the crystal structures, a methylation recognition motif was identified and found in the sequence of many tectonins from bacteria to human. Our results support a key role of tectonins in innate defense based on a distinctive and conserved type of lectin-glycan interaction.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Crystal Structures of Fungal Tectonin in Complex with O-Methylated Glycans Suggest Key Role in Innate Immune Defense.
Article2019-03-15T00:00:00ZInnate immunity is the first line of defense against pathogens and predators. To initiate a response, it relies on the detection of invaders, where lectin-carbohydrate interactions play a major role. O-Methylated glycans were previously identified as non-self epitopes and conserved targets for defense effector proteins belonging to the tectonin superfamily. Here, we present two crystal structures of Tectonin 2 from the mushroom Laccaria bicolor in complex with methylated ligands, unraveling the molecular basis for this original specificity. Furthermore, they revealed the formation of a ball-shaped tetramer with 24 binding sites distributed at its surface, resembling a small virus capsid. Based on the crystal structures, a methylation recognition motif was identified and found in the sequence of many tectonins from bacteria to human. Our results support a key role of tectonins in innate defense based on a distinctive and conserved type of lectin-glycan interaction.oai:repository.helmholtz-hzi.de:10033/6214022019-08-30T11:26:38Zcom_10033_620656col_10033_620657
Liu, Yun
Stuart, Marc C A
Buhler, Eric
Hirsch, Anna K H
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-06-18T11:57:38Z
2018-06-18T11:57:38Z
2018-05-28
1521-3927
29806088
10.1002/marc.201800099
http://hdl.handle.net/10033/621402
Dynamic proteoids are dynamic covalent analogues of proteins which are generated through the reversible polymerization of amino-acid- or peptide-derived monomers. The authors design and prepare a series of dynamic proteoids based on the reversible polycondensation of six types of dipeptide hydrazides bearing different categories of side chains. The polymerization and structures of biodynamers generated by
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
biodynamers
dynamic proteoids
polycondensation
reversible polymerization
supramolecular structures
Dynamic Proteoids Generated From Dipeptide-Based Monomers.
Article
Macromolecular rapid communications2018-06-18T11:57:38Zoai:repository.helmholtz-hzi.de:10033/6214232019-08-30T11:33:27Zcom_10033_620656col_10033_620658
Sommer, Roman
Hauck, Dirk
Titz, Alexander
HIPS, Helmholtz-Institute für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
2018-07-06T08:56:40Z
2018-07-06T08:56:40Z
23656549
10.1002/slct.201700161
http://hdl.handle.net/10033/621423
β‐Linked glycosides of N‐acetyl glucosamine are widespread in nature. Their direct synthesis is hampered by the low reactivity of GlcNAc as a glycosyl donor. We report a selective and rapid copper(II) triflate‐catalyzed two‐step synthesis of β‐glycosides of GlcNAc from cheap GlcNAc as starting material without purification of intermediates. α‐Specific glycosylation can be achieved by increasing the amount of catalyst and extending reaction times.
http://doi.wiley.com/10.1002/slct.201700161
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Efficient Two Step β-Glycoside Synthesis from -Acetyl -Glucosamine: Scope and Limitations of Copper(II) Triflate-Catalyzed Glycosylation
Article
2
15
4187
4192
ChemistrySelect2018-07-06T08:56:41Zoai:repository.helmholtz-hzi.de:10033/6214742018-09-11T01:30:01Zcom_10033_620656col_10033_620657
Liu, Yun
Stuart, Marc C A
Witte, Martin D
Buhler, Eric
Hirsch, Anna K H
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-09-10T14:06:00Z
2018-09-10T14:06:00Z
2017-11-16
1521-3765
28981987
10.1002/chem.201703584
http://hdl.handle.net/10033/621474
Dynamic proteoids are dynamic covalent analogues of proteins, which can be used as new adaptive biomaterials. We designed and synthesized a range of sugar-containing dynamic proteoid biodynamers based on the polycondensation of different types of amino acid and dipeptide hydrazides with a biological aliphatic dialdehyde and a nonbiological aromatic dialdehyde. By using the saccharide-based dialdehyde, the biocompatibility of biodynamers should be enhanced compared to previously reported biodynamers.
info:eu-repo/grantAgreement/EC/FP7/ 305064
openAccess
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
biodynamers
dynamic proteoids
equilibrium polymerization
nanostructures
supramolecular chemistry
Saccharide-Containing Dynamic Proteoids.
Article
Chemistry (Weinheim an der Bergstrasse, Germany)2018-09-10T14:06:01Zoai:repository.helmholtz-hzi.de:10033/6214752019-08-30T11:27:44Zcom_10033_620656col_10033_620657
Liu, Yun
de Vries, Jan Willem
Liu, Qing
Hartman, Alwin M
Wieland, Gerhard D
Wieczorek, Sebastian
Börner, Hans G
Wiehe, Arno
Buhler, Eric
Stuart, Marc C A
Browne, Wesley R
Herrmann, Andreas
Hirsch, Anna K H
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-09-11T11:54:22Z
2018-09-11T11:54:22Z
2018-01-19
1521-3765
29194834
10.1002/chem.201705206
http://hdl.handle.net/10033/621475
Hydrophobic drug candidates require innovative formulation agents. We designed and synthesized lipid-DNA polymers containing varying numbers of hydrophobic alkyl chains. The hydrophobicity of these amphiphiles is easily tunable by introducing a defined number of alkyl chain-modified nucleotides during standard solid-phase synthesis of DNA using an automated DNA synthesizer. We observed that the resulting self-assembled micelles solubilize the poorly water-soluble drug, meta-tetra-hydroxyphenyl-chlorin (mTHPC) used in photodynamic therapy (PDT) with high loading concentrations and loading capacities. A cell viability study showed that mTHPC-loaded micelles exhibit good biocompatibility without irradiation, and high PDT efficacy upon irradiation. Lipid-DNAs provide a novel class of drug-delivery vehicle, and hybridization of DNA offers a potentially facile route for further functionalization of the drug-delivery system with, for instance, targeting or imaging moieties.
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
amphiphiles
drug delivery
lipid-DNA
micelles
photodynamic therapy
Lipid-DNAs as Solubilizers of mTHPC.
Article
Chemistry (Weinheim an der Bergstrasse, Germany)2018-09-11T11:54:23Zoai:repository.helmholtz-hzi.de:10033/6214822019-11-20T02:02:10Zcom_10033_620613com_10033_620656col_10033_620614col_10033_620685col_10033_620657
Frank, Julia
Richter, Maximilian
de Rossi, Chiara
Lehr, Claus-Michael
Fuhrmann, Kathrin
Fuhrmann, Gregor
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-09-17T07:54:12Z
2018-09-17T07:54:12Z
2018-08-17
2045-2322
30120298
10.1038/s41598-018-30786-y
http://hdl.handle.net/10033/621482
Extracellular vesicles (EVs) are natural nanoparticles that play important roles in intercellular communication and are increasingly studied for biosignalling, pathogenesis and therapy. Nevertheless, little is known about optimal conditions for their transfer and storage, and the potential impact on preserving EV-loaded cargoes. We present the first comprehensive stability assessment of different widely available types of EVs during various storage conditions including -80 °C, 4 °C, room temperature, and freeze-drying (lyophilisation). Lyophilisation of EVs would allow easy handling at room temperature and thus significantly enhance their expanded investigation. A model enzyme, β-glucuronidase, was loaded into different types of EVs derived from mesenchymal stem cells, endothelial cells and cancer cells. Using asymmetric flow field-flow fractionation we proved that the model enzyme is indeed stably encapsulated into EVs. When assessing enzyme activity as indicator for EV stability, and in comparison to liposomes, we show that EVs are intrinsically stable during lyophilisation, an effect further enhanced by cryoprotectants. Our findings provide new insight for exploring lyophilisation as a novel storage modality and we create an important basis for standardised and advanced EV applications in biomedical research.
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
Extracellular vesicles protect glucuronidase model enzymes during freeze-drying.
Article
Scientific reports2018-09-17T07:54:13Zoai:repository.helmholtz-hzi.de:10033/6214892019-08-30T11:33:04Zcom_10033_620656col_10033_620657
Liu, Yun
Bos, I Sophie T
Oenema, Tjitske A
Meurs, Herman
Maarsingh, Harm
Hirsch, Anna K H
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-09-19T08:08:09Z
2018-09-19T08:08:09Z
2018-09-01
1873-3441
29908939
10.1016/j.ejpb.2018.06.012
http://hdl.handle.net/10033/621489
Budesonide is a hydrophobic glucocorticoid with high anti-inflammatory activity for the treatment of asthma, inflammatory bowel disease and rheumatoid arthritis. A micellar drug-delivery system based on lipid-DNA may provide a strategy to maximize its drug efficacy and reduce adverse effects. In this work, we report the use of lipid-DNAA (UU11mer), featuring two hydrophobic alkyl chains and forming micelles at a comparatively low critical micelle concentration, to render budesonide water-soluble with a high loading capacity (LC). The inhibition of interleukin-8 (IL-8) release shows that the new delivery system retains the inhibitory activity in cell-based assays. In conclusion, this research provides a novel approach to formulate and administer budesonide in a non-invasive manner, which dramatically improves its water-solubility while retaining its bioavailability.
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
Anti-inflammatory
Budesonide
Drug delivery
Lipid-DNA
Solubility
Delivery system for budesonide based on lipid-DNA.
Article
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V
oai:repository.helmholtz-hzi.de:10033/6214932018-09-25T06:51:10Zcom_10033_620656col_10033_620657
Liu, Yun
Bos, I Sophie T
Oenema, Tjitske A
Meurs, Herman
Maarsingh, Harm
Hirsch, Anna K H
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-09-24T14:01:09Z
2018-09-24T14:01:09Z
2018-09-01
1873-3441
29908939
10.1016/j.ejpb.2018.06.012
http://hdl.handle.net/10033/621493
Budesonide is a hydrophobic glucocorticoid with high anti-inflammatory activity for the treatment of asthma, inflammatory bowel disease and rheumatoid arthritis. A micellar drug-delivery system based on lipid-DNA may provide a strategy to maximize its drug efficacy and reduce adverse effects. In this work, we report the use of lipid-DNAA (UU11mer), featuring two hydrophobic alkyl chains and forming micelles at a comparatively low critical micelle concentration, to render budesonide water-soluble with a high loading capacity (LC). The inhibition of interleukin-8 (IL-8) release shows that the new delivery system retains the inhibitory activity in cell-based assays. In conclusion, this research provides a novel approach to formulate and administer budesonide in a non-invasive manner, which dramatically improves its water-solubility while retaining its bioavailability.
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
Anti-inflammatory
Budesonide
Drug delivery
Lipid-DNA
Solubility
Delivery system for budesonide based on lipid-DNA.
Article
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V
oai:repository.helmholtz-hzi.de:10033/6215052018-10-02T01:57:40Zcom_10033_620656col_10033_620658
Calvert, Matthew B
Mayer, Christoph
Titz, Alexander
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-10-01T13:29:37Z
2018-10-01T13:29:37Z
2017-01-01
1860-5397
30018663
10.3762/bjoc.13.261
http://hdl.handle.net/10033/621505
A novel synthesis of 1,6-anhydro-N-acetylmuramic acid is described, which proceeds in only five steps from the cheap starting material N-acetylglucosamine. This efficient synthesis should enable future studies into the importance of 1,6-anhydromuramic acid in bacterial cell wall recycling processes.
Attribution-NonCommercial-ShareAlike 3.0 United States
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N-acetylmuramic acid
anhydrosugars
antibiotic resistance
bacterial cell wall recycling
carbohydrate synthesis
An efficient synthesis of 1,6-anhydro--acetylmuramic acid from -acetylglucosamine.
Article
Beilstein journal of organic chemistry2018-10-01T13:29:37Zoai:repository.helmholtz-hzi.de:10033/6215152019-08-30T11:29:46Zcom_10033_620656col_10033_620657
Brengel, Christian
Thomann, Andreas
Schifrin, Alexander
Allegretta, Giuseppe
Kamal, Ahmed A M
Haupenthal, Jörg
Schnorr, Isabell
Cho, Sang Hyun
Franzblau, Scott G
Empting, Martin
Eberhard, Jens
Hartmann, Rolf W
HIPS, Helmholtz-Institut für pharmazeutische Forschung Saarland, Universitätscampus 8.1, 66123 Saarbrücken, Germany.
2018-10-11T14:07:57Z
2018-10-11T14:07:57Z
2017-10-09
1860-7187
28815923
10.1002/cmdc.201700363
http://hdl.handle.net/10033/621515
The development of novel antimycobacterial agents against Mycobacterium tuberculosis (Mtb) is urgently required due to the appearance of multidrug resistance (MDR) combined with complicated long-term treatment. CYP121 was shown to be a promising novel target for inhibition of mycobacterial growth. In this study, we describe the rational discovery of new CYP121 inhibitors by a systematic screening based on biophysical and microbiological methods. The best hits originating from only one structural class gave initial information about molecular motifs required for binding and activity. The initial screening procedure was followed by mode-of-action studies and further biological characterizations. The results demonstrate superior antimycobacterial efficacy and a decreased toxicity profile of our frontrunner compound relative to the reference compound econazole. Due to its low molecular weight, promising biological profile, and physicochemical properties, this compound is an excellent starting point for further rational optimization.
Attribution-NonCommercial-ShareAlike 3.0 United States
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Mycobacterium tuberculosis
anti-infectives
biophysics
inhibitors
screening
Biophysical Screening of a Focused Library for the Discovery of CYP121 Inhibitors as Novel Antimycobacterials.
Article
ChemMedChem2018-10-11T14:07:58Zoai:repository.helmholtz-hzi.de:10033/6215322019-08-30T11:29:40Zcom_10033_620656col_10033_620658
Calvert, Matthew B
Jumde, Varsha R
Titz, Alexander
2018-11-02T11:37:03Z
2018-11-02T11:37:03Z
IPS, Helmholtz-Institut füt Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
1860-5397
10.3762/bjoc.14.239
http://hdl.handle.net/10033/621532
The rapid development of antimicrobial resistance is threatening mankind to such an extent that the World Health Organization expects more deaths from infections than from cancer in 2050 if current trends continue. To avoid this scenario, new classes of anti-infectives must urgently be developed. Antibiotics with new modes of action are needed, but other concepts are also currently being pursued. Targeting bacterial virulence as a means of blocking pathogenicity is a promising new strategy for disarming pathogens. Furthermore, it is believed that this new approach is less susceptible towards resistance development. In this review, recent examples of anti-infective compounds acting on several types of bacterial targets, e.g., adhesins, toxins and bacterial communication, are described.
https://www.beilstein-journals.org/bjoc/articles/14/239
Attribution-NonCommercial-ShareAlike 3.0 United States
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antimicrobial resistance
bacterial adhesins
bacterial toxins
pathoblockers
quorum sensing
Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections
Article
14
2607
2617
Beilstein Journal of Organic Chemistry2018-11-02T11:37:03Zoai:repository.helmholtz-hzi.de:10033/6215552019-08-30T11:31:44Zcom_10033_620656col_10033_620657
Vasile, Francesca
Della Volpe, Serena
Ambrosio, Francesca Alessandra
Costa, Giosuè
Unver, M Yagiz
Zucal, Chiara
Rossi, Daniela
Martino, Emanuela
Provenzani, Alessandro
Hirsch, Anna K H
Alcaro, Stefano
Potenza, Donatella
Collina, Simona
HIPS, Helmholtz-Institut füt Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2018-11-13T11:41:25Z
2018-11-13T11:41:25Z
2018-09-13
2045-2322
30214075
10.1038/s41598-018-32084-z
http://hdl.handle.net/10033/621555
Post-transcriptional processes have been recognised as pivotal in the control of gene expression, and impairments in RNA processing are reported in several pathologies (i.e., cancer and neurodegeneration). Focusing on RNA-binding proteins (RBPs), the involvement of Embryonic Lethal Abnormal Vision (ELAV) or Hu proteins and their complexes with target mRNAs in the aetiology of various dysfunctions, has suggested the great potential of compounds able to interfere with the complex stability as an innovative pharmacological strategy for the treatment of numerous diseases. Here, we present a rational follow-up investigation of the interaction between ELAV isoform HuR and structurally-related compounds (i.e., flavonoids and coumarins), naturally decorated with different functional groups, by means of STD-NMR and Molecular Modelling. Our results represent the foundation for the development of potent and selective ligands able to interfere with ELAV-RNA complexes.
Attribution-NonCommercial-ShareAlike 3.0 United States
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Exploration of ligand binding modes towards the identification of compounds targeting HuR: a combined STD-NMR and Molecular Modelling approach.
Article
Scientific reports2018-11-13T11:41:25Zoai:repository.helmholtz-hzi.de:10033/6215692019-08-30T11:29:43Zcom_10033_620656col_10033_620657
Salah, Mohamed
Abdelsamie, Ahmed S
Frotscher, Martin
HIPS, Helmholtz-Institut füt Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2018-11-15T14:23:17Z
2018-11-15T14:23:17Z
2018-10-15
1872-8057
30336189
10.1016/j.mce.2018.10.001
http://hdl.handle.net/10033/621569
During the past 25 years, the modulation of estrogen action by inhibition of 17β-hydroxysteroid dehydrogenase types 1 and 2 (17β-HSD1 and 17β-HSD2), respectively, has been pursued intensively. In the search for novel treatment options for estrogen-dependent diseases (EDD) and in order to explore estrogenic signaling pathways, a large number of steroidal and nonsteroidal inhibitors of these enzymes has been described in the literature. The present review gives a survey on the development of inhibitor classes as well as the structural formulas and biological properties of their most interesting representatives. In addition, rationally designed dual inhibitors of both 17β-HSD1 and steroid sulfatase (STS) as well as the first inhibitors of 17β-HSD14 are covered.
Attribution-NonCommercial-ShareAlike 3.0 United States
http://creativecommons.org/licenses/by-nc-sa/3.0/us/
Enzyme inhibitors
Estrogen dependent diseases
Hydroxysteroid dehydrogenases
Steroidogenic enzymes
Inhibitors of 17β-hydroxysteroid dehydrogenase type 1, 2 and 14: Structures, biological activities and future challenges.
Article
Molecular and cellular endocrinology
oai:repository.helmholtz-hzi.de:10033/6216632019-08-30T11:33:27Zcom_10033_620613com_10033_620656com_10033_620644com_10033_620618col_10033_620614col_10033_620657col_10033_620619col_10033_620646
Castoldi, Arianna
Empting, Martin
De Rossi, Chiara
Mayr, Karsten
Dersch, Petra
Hartmann, Rolf
Müller, Rolf
Gordon, Sarah
Lehr, Claus-Michael
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-01-18T15:45:31Z
2019-01-18T15:45:31Z
2018-12-05
Pharm Res. 2018 Dec 5;36(1):22. doi: 10.1007/s11095-018-2521-3.
1573-904X
30519925
10.1007/s11095-018-2521-3
http://hdl.handle.net/10033/621663
Pharmaceutical research
The objective of this work was to evaluate the potential of polymeric spherical and aspherical invasive nanocarriers, loaded with antibiotic, to access and treat intracellular bacterial infections. Aspherical nanocarriers were prepared by stretching of spherical precursors, and both aspherical and spherical nanocarriers were surface-functionalized with the invasive protein InvA497. The relative uptake of nanocarriers into HEp-2 epithelial cells was then assessed. Nanocarriers were subsequently loaded with a preparation of the non-permeable antibiotic gentamicin, and tested for their ability to treat HEp-2 cells infected with the enteroinvasive bacterium Shigella flexneri. InvA497-functionalized nanocarriers of both spherical and aspherical shape showed a significantly improved rate and extent of uptake into HEp-2 cells in comparison to non-functionalized nanocarriers. Functionalized and antibiotic-loaded nanocarriers demonstrated a dose dependent killing of intracellular S. flexneri. A slight but significant enhancement of intracellular bacterial killing was also observed with aspherical as compared to spherical functionalized nanocarriers at the highest tested concentration. InvA497-functionalized, polymer-based nanocarriers were able to efficiently deliver a non-permeable antibiotic across host cell membranes to affect killing of intracellular bacteria. Functionalized nanocarriers with an aspherical shape showed an interesting future potential for intracellular infection therapy.
en
Springer
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
AOT-gentamicin
aspherical nanoparticles
bacteriomimetic nanocarriers
intracellular infection
invasin
Aspherical and Spherical InvA497-Functionalized Nanocarriers for Intracellular Delivery of Anti-Infective Agents.
Article
Pharmaceutical research2019-01-18T15:45:32Zoai:repository.helmholtz-hzi.de:10033/6216992019-02-20T01:22:06Zcom_10033_620656col_10033_620657
2019-02-19T15:09:37Z
2019-02-19T15:09:37Z
2018-09-12
2366-3987
10.1002/adtp.201800066
http://hdl.handle.net/10033/621699
Advanced Therapeutics
In an attempt to find new antibiotics, novel ways of interfering with important biological functions should be explored, especially with those which are necessary or even irreplaceable for bacterial survival, growth, and virulence. The purpose of this review is to highlight B‐type vitamin transporters from the energy‐coupling factor (ECF) family, which are not present in humans, as potential antimicrobial targets. In addition, a druggability analysis of an ECF transporter for folic acid and sequence‐conservation studies in seven prominent pathogens revealed new druggable pockets. Evaluation of the presence of de novo biosynthetic routes for the vitamins in question in the seven pathogens confirmed that this target class holds promise for the discovery of antimicrobial drugs with a new mechanism of action, possibly on a broad‐spectrum level.
Wiley-Blackwell
'info:eu-repo/grantAgreement/EC/H2020//757913
openAccess
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
Energy‐Coupling Factor Transporters as Novel Antimicrobial Targets
Article
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.2019-02-19T15:09:38Zoai:repository.helmholtz-hzi.de:10033/6217002021-07-23T12:59:03Zcom_10033_620656col_10033_620657
Bousis, Spyridon
Diamanti, Eleonora
Slotboom, Dirk J.
Hirsch, Anna K. H.
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-02-20T10:42:06Z
2019-02-20T10:42:06Z
2019-02
10.1002/adtp.201800066
https://onlinelibrary.wiley.com/doi/epdf/10.1002/adtp.201800066
http://hdl.handle.net/10033/621700
2366-3987
Advanced Therapeutics
In an attempt to find new antibiotics, novel ways of interfering with important biological functions should be explored, especially with those which are necessary or even irreplaceable for bacterial survival, growth, and virulence. The purpose of this review is to highlight B‐type vitamin transporters from the energy‐coupling factor (ECF) family, which are not present in humans, as potential antimicrobial targets. In addition, a druggability analysis of an ECF transporter for folic acid and sequence‐conservation studies in seven prominent pathogens revealed new druggable pockets. Evaluation of the presence of de novo biosynthetic routes for the vitamins in question in the seven pathogens confirmed that this target class holds promise for the discovery of antimicrobial drugs with a new mechanism of action, possibly on a broad‐spectrum level.
en
Wiley-Blackwell
info:eu-repo/grantAgreement/EC/H2020/757913
openAccess
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
antimicrobials
B-type vitamins
energy coupling factor transporters
S-components
uptake
Energy‐Coupling Factor Transporters as Novel Antimicrobial Targets
Article2019-02-20T10:42:06Zoai:repository.helmholtz-hzi.de:10033/6217282019-08-30T11:31:49Zcom_10033_620656col_10033_620657
Bestgen, Benoît
Kufareva, Irina
Seetoh, Weiguang
Abell, Chris
Hartmann, Rolf W
Abagyan, Ruben
Le Borgne, Marc
Filhol, Odile
Cochet, Claude
Lomberget, Thierry
Engel, Matthias
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-03-20T10:55:28Z
2019-03-20T10:55:28Z
2019-02-28
J Med Chem. 2019 Feb 28;62(4):1817-1836. doi: 10.1021/acs.jmedchem.8b01765. Epub 2019 Feb 13
1520-4804
30689946
10.1021/acs.jmedchem.8b01765
http://hdl.handle.net/10033/621728
Journal of Medicinal Chemistry
Protein CK2 has gained much interest as an anticancer drug target in the past decade. We had previously described the identification of a new allosteric site on the catalytic α-subunit, along with first small molecule ligands based on the 4-(4-phenylthiazol-2-ylamino)benzoic acid scaffold. In the present work, structure optimizations guided by a binding model led to the identification of the lead compound 2-hydroxy-4-((4-(naphthalen-2-yl)thiazol-2-yl)amino)benzoic acid (27), showing a submicromolar potency against purified CK2α (IC
en
American Chemical Society
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
CK2
kinase inhibitors
allosteric inhibition
kinase selectivity
anti-cancer
2-Aminothiazole Derivatives as Selective Allosteric Modulators of the Protein Kinase CK2. 2. Structure-Based Optimization and Investigation of Effects Specific to the Allosteric Mode of Action.
Article
Journal of medicinal chemistry
oai:repository.helmholtz-hzi.de:10033/6217442019-08-30T11:32:36Zcom_10033_620656col_10033_620657
Schmidt, Nico
Li, Jun
Gottardi, Stefano
Moreno-Lopez, Juan Carlos
Enache, Mihaela
Monjas, Leticia
van der Vlag, Ramon
Havenith, Remco W A
Hirsch, Anna K H
Stöhr, Meike
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-04-11T11:36:13Z
2019-04-11T11:36:13Z
2019-04-01
Chemistry. 2019 Apr 1;25(19):5065-5070. doi: 10.1002/chem.201806312. Epub 2019 Mar 12.
1521-3765
30657213
10.1002/chem.201806312
http://hdl.handle.net/10033/621744
Chemistry - A European Journal
A comparative study on the self-assembly of sexiphenyl-dicarbonitrile on highly oriented pyrolytic graphite and single-layer graphene on Cu(111) is presented. Despite an overall low molecule-substrate interaction, the close-packed structures exhibit a peculiar shift repeating every four to five molecules. This shift has hitherto not been reported for similar systems and is hence a unique feature induced by the graphitic substrates.
Wiley-Blackwell
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
graphene
nanostructures
scanning probe microscopy
self-assembly
surface analysis
Comparing the Self-Assembly of Sexiphenyl-Dicarbonitrile on Graphite and Graphene on Cu(111).
Article
Chemistry (Weinheim an der Bergstrasse, Germany)2019-04-11T11:36:14Zoai:repository.helmholtz-hzi.de:10033/6218312019-08-30T11:32:13Zcom_10033_620656col_10033_620657
Li, Jun
Solianyk, Leonid
Schmidt, Nico
Baker, Brian
Gottardi, Stefano
Moreno Lopez, Juan Carlos
Enache, Mihaela
Monjas, Leticia
van der Vlag, Ramon
Havenith, Remco W A
Hirsch, Anna K H
Stöhr, Meike
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-06-26T13:22:47Z
2019-06-26T13:22:47Z
2019-05-23
J Phys Chem C Nanomater Interfaces. 2019 May 23;123(20):12730-12735. doi: 10.1021/acs.jpcc.9b00326. Epub 2019 Apr 30.
1932-7447
31156737
10.1021/acs.jpcc.9b00326
http://hdl.handle.net/10033/621831
Journal of Physical Chemistry C
We report the formation of one- and two-dimensional metal-organic coordination structures from para-hexaphenyl-dicarbonitrile (NC-Ph6-CN) molecules and Cu atoms on graphene epitaxially grown on Ir(111). By varying the stoichiometry between the NC-Ph6-CN molecules and Cu atoms, the dimensionality of the metal-organic coordination structures could be tuned: for a 3:2 ratio, a two-dimensional hexagonal porous network based on threefold Cu coordination was observed, while for a 1:1 ratio, one-dimensional chains based on twofold Cu coordination were formed. The formation of metal-ligand bonds was supported by imaging the Cu atoms within the metal-organic coordination structures with scanning tunneling microscopy. Scanning tunneling spectroscopy measurements demonstrated that the electronic properties of NC-Ph6-CN molecules and Cu atoms were different between the two-dimensional porous network and one-dimensional molecular chains.
American Society of Chemistry
Attribution-NonCommercial-ShareAlike 4.0 International
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Low-Dimensional Metal-Organic Coordination Structures on Graphene.
Article
The journal of physical chemistry. C, Nanomaterials and interfaces2019-06-26T13:22:48Zoai:repository.helmholtz-hzi.de:10033/6218442019-08-30T11:26:39Zcom_10033_620656col_10033_620657
Prismawan, Deka
van der Vlag, Ramon
Guo, Hao
Dekker, Frank J
Hirsch, Anna K H
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-07-03T14:07:18Z
2019-07-03T14:07:18Z
2019-05-01
Helv Chim Acta. 2019 May;102(5):e1900040. doi: 10.1002/hlca.201900040. Epub 2019 May 2.
0018-019X
31231138
10.1002/hlca.201900040
http://hdl.handle.net/10033/621844
Helvetica Chimica Acta
Human 15-lipoxygenase-1 (15-LOX-1) belongs to the class of lipoxygenases, which catalyze oxygenation of polyunsaturated fatty acids, such as arachidonic and linoleic acid. Recent studies have shown that 15-LOX-1 plays an important role in physiological processes linked to several diseases such as airway inflammation disease, coronary artery disease, and several types of cancer such as rectal, colon, breast and prostate cancer. In this study, we aimed to extend the structural diversity of 15-LOX-1 inhibitors, starting from the recently identified indolyl core. In order to find new scaffolds, we employed a combinatorial approach using various aromatic aldehydes and an aliphatic hydrazide tail. This scaffold-hopping study resulted in the identification of the 3-pyridylring as a suitable replacement of the indolyl core with an inhibitory activity in the micromolar range (IC50=16±6 μm) and a rapid and efficient structure-activity relationship investigation.
en
Wiley-Blackwell
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
15-lipoxygenase-1
acylhydrazone
combinatorial chemistry
enzyme inhibitors
structure–activity relationships
Replacement of an Indole Scaffold Targeting Human 15-Lipoxygenase-1 Using Combinatorial Chemistry.
Article
Helvetica chimica acta2019-07-03T14:07:19Zoai:repository.helmholtz-hzi.de:10033/6218462019-08-30T11:24:27Zcom_10033_620656col_10033_620657
Hartman, Alwin M.
Gierse, Robin M.
Hirsch, Anna K. H.
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-07-04T12:52:19Z
2019-07-04T12:52:19Z
2019-05-03
http://hdl.handle.net/10033/621846
European Journal of Organic Chemistry
Dynamic combinatorial chemistry (DCC) is a powerful tool to identify bioactive compounds. This efficient technique allows the target to select its own binders and circumvents the need for synthesis and biochemical evaluation of all individual derivatives. An ever‐increasing number of publications report the use of DCC on biologically relevant target proteins. This minireview complements previous reviews by focusing on the experimental protocol and giving detailed examples of essential steps and factors that need to be considered, such as protein stability, buffer composition and cosolvents.
en
Wiley
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
Protein-Templated Dynamic Combinatorial Chemistry: Brief Overview and Experimental Protocol
Article2019-07-04T12:52:19Zoai:repository.helmholtz-hzi.de:10033/6218492019-08-30T11:26:10Zcom_10033_620656col_10033_620657
Kirsch, Philine
Jakob, Valentin
Oberhausen, Kevin
Stein, Saskia C
Cucarro, Ivano
Schulz, Thomas F
Empting, Martin
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-07-05T14:38:50Z
2019-07-05T14:38:50Z
2019-04-25
J Med Chem. 2019 Apr 25;62(8):3924-3939. doi: 10.1021/acs.jmedchem.8b01827. Epub 2019 Apr 12.
1520-4804
30888817
10.1021/acs.jmedchem.8b01827
http://hdl.handle.net/10033/621849
Journal of Medicinal Chemistry
The latency-associated nuclear antigen (LANA) is required for latent replication and persistence of Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8. It acts via replicating and tethering the virus episome to the host chromatin and exerts other functions. We conceived a new approach for the discovery of antiviral drugs to inhibit the interaction between LANA and the viral genome. We applied a biophysical screening cascade and identified the first LANA binders from small, structurally diverse compound libraries. Starting from a fragment-sized scaffold, we generated optimized hits via fragment growing using a dedicated fluorescence-polarization-based assay as the structure-activity-relationship driver. We improved compound potency to the double-digit micromolar range. Importantly, we qualified the resulting hit through orthogonal methods employing EMSA, STD-NMR, and MST methodologies. This optimized hit provides an ideal starting point for subsequent hit-to-lead campaigns providing evident target-binding, suitable ligand efficiencies, and favorable physicochemical properties.
en
American Chemical Society
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
Fragment-Based Discovery of a Qualified Hit Targeting the Latency-Associated Nuclear Antigen of the Oncogenic Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8.
Article
Journal of medicinal chemistry
oai:repository.helmholtz-hzi.de:10033/6218502019-08-30T11:26:40Zcom_10033_620656col_10033_620658
Lepsik, Martin
Sommer, Roman
Kuhaudomlarp, Sakonwan
Lelimousin, Mickaël
Paci, Emanuele
Varrot, Annabelle
Titz, Alexander
Imberty, Anne
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-07-08T08:34:30Z
2019-07-08T08:34:30Z
2019-09-01
Eur J Med Chem. 2019 Sep 1;177:212-220. doi: 10.1016/j.ejmech.2019.05.049. Epub 2019 May 18.
1768-3254
31146126
10.1016/j.ejmech.2019.05.049
http://hdl.handle.net/10033/621850
European Journal of Medicinal Chemistry
Pathogenic micro-organisms utilize protein receptors (lectins) in adhesion to host tissues, a process that in some cases relies on the interaction between lectins and human glycoconjugates. Oligosaccharide epitopes are recognized through their three-dimensional structure and their flexibility is a key issue in specificity. In this paper, we analysed by X-ray crystallography the structures of the LecB lectin from two strains of Pseudomonas aeruginosa in complex with Lewis x oligosaccharide present on cell surfaces of human tissues. An unusual conformation of the glycan was observed in all binding sites with a non-canonical syn orientation of the N-acetyl group of N-acetyl-glucosamine. A PDB-wide search revealed that such an orientation occurs only in 4% of protein/carbohydrate complexes. Theoretical chemistry calculations showed that the observed conformation is unstable in solution but stabilised by the lectin. A reliable description of LecB/Lewis x complex by force field-based methods had proven especially challenging due to the special feature of the binding site, two closely apposed Ca2+ ions which induce strong charge delocalisation. By comparing various force-field parametrisations, we propose a general strategy which will be useful in near future for designing carbohydrate-based ligands (glycodrugs) against other calcium-dependent protein receptors.
en
Elsevier
nfo:eu-repo/grantAgreement/EC/H2020/795605
embargoedAccess
Attribution-NonCommercial-ShareAlike 4.0 International
http://creativecommons.org/licenses/by-nc-sa/4.0/
Calcium ion
Carbohydrate
Lectin
Molecular dynamics
N-Acetyl
Quantum effect
Induction of rare conformation of oligosaccharide by binding to calcium-dependent bacterial lectin: X-ray crystallography and modelling study.
Article
European journal of medicinal chemistry
oai:repository.helmholtz-hzi.de:10033/6218792019-08-30T11:26:10Zcom_10033_620656col_10033_620657
Röhrig, Teresa
Kirsch, Verena
Schipp, Dorothea
Galan, Jens
Richling, Elke
HIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
2019-07-16T13:28:20Z
2019-07-16T13:28:20Z
2019-06-19
J Agric Food Chem. 2019 Jun 19;67(24):6792-6797. doi: 10.1021/acs.jafc.9b01567. Epub 2019 Jun 10.
1520-5118
31134806
10.1021/acs.jafc.9b01567
http://hdl.handle.net/10033/621879
Journal of agricultural and food chemistry
The dominant anthocyanins in blackcurrant are delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside. Data on their absorption and distribution in the human body are limited. Therefore, we performed a human pilot study on five healthy male volunteers consuming a blackcurrant (Ribes nigrum L.) extract. The rutinosides and their degradation products gallic acid and protocatechuic acid were determined in plasma and urine. The rutinosides’ concentrations peaked in both plasma and urine samples within 2 h of extract ingestion. The recoveries of delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside from urine samples were 0.040 ± 0.011% and 0.048 ± 0.016%, respectively, over a 48 h period. Protocatechuic acid concentration increased significantly after ingestion of the blackcurrant extract. Our results show that after ingestion of a blackcurrant extract containing delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, significant quantities of biologically active compounds circulated in the plasma and were excreted via urine. Furthermore, these results contribute to the understanding of anthocyanin metabolism in humans.
en
American Chemical Society
Attribution-NonCommercial-ShareAlike 4.0 International
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L.
anthocyanin
bioavailability
blackcurrant
rutinoside
Absorption of Anthocyanin Rutinosides after Consumption of a Blackcurrant ( Ribes nigrum L.) Extract.
Article
Journal of agricultural and food chemistry2019-07-16T13:28:20Zdim///com_10033_620656/100