• Delivery system for budesonide based on lipid-DNA.

      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. (2018-09-01)
      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.
    • Delivery system for budesonide based on lipid-DNA.

      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. (2018-09-01)
      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.
    • Dynamic Proteoids Generated From Dipeptide-Based Monomers.

      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. (2018-05-28)
      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
    • 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.

      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. (2018-03)
      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.
    • Lipid-DNAs as Solubilizers of mTHPC.

      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. (2018-01-19)
      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.
    • Phage Display on the Anti-infective Target 1-Deoxy-d-xylulose-5-phosphate Synthase Leads to an Acceptor-Substrate Competitive Peptidic Inhibitor.

      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. (2018-01-04)
      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.
    • Dynamic Combinatorial Chemistry to Identify Binders of ThiT, an S-Component of the Energy-Coupling Factor Transporter for Thiamine.

      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. (2017-10-20)
      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.
    • Biophysical Screening of a Focused Library for the Discovery of CYP121 Inhibitors as Novel Antimycobacterials.

      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. (2017-10-09)
      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.
    • Saccharide-Containing Dynamic Proteoids.

      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. (2017-10-05)
      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.
    • Discovery of a Potent Inhibitor Class with High Selectivity toward Clostridial Collagenases.

      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. (2017-09-13)
      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.
    • Semi-synthetic vNAR libraries screened against therapeutic antibodies primarily deliver anti-idiotypic binders.

      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. (2017-08-29)
      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.
    • Drifting of heme-coordinating group in imidazolylmethylxanthones leading to improved selective inhibition of CYP11B1.

      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. (2017-08-02)
      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.
    • Structure-functionality relationship and pharmacological profiles of Pseudomonas aeruginosa alkylquinolone quorum sensing modulators.

      Kamal, Ahmed A M; Petrera, Lucia; Eberhard, Jens; Hartmann, Rolf W.; Helmholtz-Institu für pharmazeutische Forschung Saarland,, Universitätscampus E8.1, 66123 Saarbrücken, Germany. (2017-05-31)
      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.
    • Regulation of Burkholderia cenocepacia biofilm formation by RpoN and the c-di-GMP effector BerB.

      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. (2017-04-16)
      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.
    • In-depth Profiling of MvfR-Regulated Small Molecules in Pseudomonas aeruginosa after Quorum Sensing Inhibitor Treatment.

      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)
      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.
    • Structure-Activity Relationships of 2-Sufonylpyrimidines as Quorum-Sensing Inhibitors to Tackle Biofilm Formation and eDNA Release of Pseudomonas aeruginosa.

      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. (2016-11-21)
      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.
    • Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors.

      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. (2016-07-07)
      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.
    • Discovery of the first small-molecule CsrA-RNA interaction inhibitors using biophysical screening technologies.

      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. (2016-06)
      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).
    • Single-domain antibodies for biomedical applications.

      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. (2016-02)
      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.
    • Preparation of nanosized coacervates of positive and negative starch derivatives intended for pulmonary delivery of proteins

      Barthold, S.; Kletting, S.; Taffner, J.; de Souza Carvalho-Wodarz, C.; Lepeltier, E.; Loretz, B.; Lehr, C M; Helmholtz-Institut für pharmaceutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany. (2016)