Recent Submissions

  • Solution structure of the Equine Infectious Anemia Virus p9 protein: a rationalization of its different ALIX binding requirements compared to the analogous HIV-p6 protein

    Sharma, Alok; Bruns, Karsten; Röder, René; Henklein, Peter; Votteler, Jörg; Wray, Victor; Schubert, Ulrich (2009-12-17)
    Abstract Background The equine infection anemia virus (EIAV) p9 Gag protein contains the late (L-) domain required for efficient virus release of nascent virions from the cell membrane of infected cell. Results In the present study the p9 protein and N- and C-terminal fragments (residues 1-21 and 22-51, respectively) were chemically synthesized and used for structural analyses. Circular dichroism and 1H-NMR spectroscopy provide the first molecular insight into the secondary structure and folding of this 51-amino acid protein under different solution conditions. Qualitative 1H-chemical shift and NOE data indicate that in a pure aqueous environment p9 favors an unstructured state. In its most structured state under hydrophobic conditions, p9 adopts a stable helical structure within the C-terminus. Quantitative NOE data further revealed that this α-helix extends from Ser-27 to Ser-48, while the N-terminal residues remain unstructured. The structural elements identified for p9 differ substantially from that of the functional homologous HIV-1 p6 protein. Conclusions These structural differences are discussed in the context of the different types of L-domains regulating distinct cellular pathways in virus budding. EIAV p9 mediates virus release by recruiting the ALG2-interacting protein X (ALIX) via the YPDL-motif to the site of virus budding, the counterpart of the YPXnL-motif found in p6. However, p6 contains an additional PTAP L-domain that promotes HIV-1 release by binding to the tumor susceptibility gene 101 (Tsg101). The notion that structures found in p9 differ form that of p6 further support the idea that different mechanisms regulate binding of ALIX to primary versus secondary L-domains types.
  • Formation, Location, and Regulation of Endo-1,4-beta-Glucanases and beta-Glucosidases from Cellulomonas uda.

    Stoppok, W; Rapp, P; Wagner, F; Gesellschaft fur Biotechnologische Forschung mbH, D-38124 Braunschweig, Germany. (1982-07)
    The formation and location of endo-1,4-beta-glucanases and beta-glucosidases were studied in cultures of Cellulomonas uda grown on microcrystalline cellulose, carboxymethyl cellulose, printed newspaper, and some mono- or disaccharides. Endo-1,4-Glucanases were found to be extracellular, but a very small amount of cell-bound endo-1,4-beta-glucanase was considered to be the basal endoglucanase level of the cells. The formation of extracellular endo-1,4-beta-glucanases was induced by cellobiose and repressed by glucose. Extracellular endoglucanase activity was inhibited by cellobiose but not by glucose. beta-Glucosidases, on the other hand, were formed constitutively and found to be cell bound. beta-Glucosidase activity was inhibited noncompetitively by glucose. Some characteristics such as the optimal pH for and the thermostability of the endoglucanases and beta-glucosidases and the end products of cellulose degradation were determined.
  • Induced production of depsipeptides by co-culturing Fusarium tricinctum and Fusarium begoniae

    Wang, Jian-ping; Lin, Wenhan; Wray, Victor; Lai, Daowan; Proksch, Peter (2013-10-01)
  • Callyaerin G, a new cytotoxic cyclic peptide from the marine sponge Callyspongia aerizusa

    Ibrahim, Sabrin R. M.; Edrada-Ebel, RuAngelie; Mohamed,Gamal A.; Youssef, Diaa T. A; Wray, Victor; Proksch, Peter; Helmholz Centre for Infection research, D-38124 Braunschweig, Germany (Arkat, 2008-04-16)
  • Pullularins E and F, Two New Peptides from the Endophytic Fungus Bionectria ochroleuca Isolated from the Mangrove Plant Sonneratia caseolaris.

    Ebrahim, Weaam; Kjer, Julia; El Amrani, Mustapha; Wray, Victor; Lin, Wenhan; Ebel, Rainer; Lai, Daowan; Proksch, Peter; Institute of Pharmaceutical Biology and Biotechnology, Heinrich-Heine University, Universitaetsstrasse 1, D-40225 Duesseldorf, Germany; Email: weel-001@uni-duesseldorf.de or weaamnabil@mans.edu.eg (W.E.); jacob.julia@web.de (J.K.); mustapha.elamrani@uni-duesseldorf.de (M.E.A.). (2012-05)
    Chemical investigation of the EtOAc extract of the endophytic fungus Bionectria ochroleuca, isolated from the inner leaf tissues of the plant Sonneratia caseolaris (Sonneratiaceae) from Hainan island (China), yielded two new peptides, pullularins E and F (1 and 2) together with three known compounds (3-5). The structures of the new compounds were unambiguously determined on the basis of one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. The absolute configurations of amino acids were determined by HPLC analysis of acid hydrolysates using Marfey's method. The isolated compounds exhibited pronounced to moderate cytotoxic activity against the mouse lymphoma cells (L5178Y) with EC(50) values ranging between 0.1 and 6.7 µg/mL.
  • Novel peroxidases of Marasmius scorodonius degrade beta-carotene.

    Scheibner, M; Hülsdau, B; Zelena, K; Nimtz, M; de Boer, L; Berger, RG; Zorn, H; Zentrum Angewandte Chemie, Institut für Lebensmittelchemie der Universität Hannover, Wunstorfer Straße 14, 30453, Hannover, Germany. (2008-01)
    Two extracellular enzymes (MsP1 and MsP2) capable of efficient beta-carotene degradation were purified from culture supernatants of the basidiomycete Marasmius scorodonius (garlic mushroom). Under native conditions, the enzymes exhibited molecular masses of ~150 and ~120 kDa, respectively. SDS-PAGE and mass spectrometric data suggested a composition of two identical subunits for both enzymes. Biochemical characterisation of the purified proteins showed isoelectric points of 3.7 and 3.5, and the presence of heme groups in the active enzymes. Partial amino acid sequences were derived from N-terminal Edman degradation and from mass spectrometric ab initio sequencing of internal peptides. cDNAs of 1,604 to 1,923 bp, containing open reading frames (ORF) of 508 to 513 amino acids, respectively, were cloned from a cDNA library of M. scorodonius. These data suggest glycosylation degrees of ~23% for MsP1 and 8% for MsP2. Databank homology searches revealed sequence homologies of MsP1 and MsP2 to unusual peroxidases of the fungi Thanatephorus cucumeris (DyP) and Termitomyces albuminosus (TAP).
  • Preparative Isolation and Purification of Flavonoids and Protocatechuic Acid from Sea Buckthorn Juice Concentrate (Hippophae rhamnoides) by High-Speed Counter-Current Chromatography

    Gutzeit, D.; Wray, Victor; Winterhalter, P.; Jerz, Gerold; Institute of Food Chemistry, Technical University of Braunschweig (Springer Science Business Media, 2007)
  • Formation and Identification of Interfacial-Active Glycolipids from Resting Microbial Cells

    Li, Zu-Yi; Lang, Siegmund; Wagner, Fritz; Witte, Ludger; Wray, Victor (1984-09)