tailieunhanh - Báo cáo khoa học: Flagellar glycosylation in Clostridium botulinum

Flagellins fromClostridium botulinumwere shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains ofC. botulinumdemonstrated that the protein is modified by a novel glycan moiety of mass 417 Da in O-linkage. | ễFEBS Journal Flagellar glycosylation in Clostridium botulinum Susan M. Twine1 Catherine J. Paul1 2 Evgeny Vinogradov1 David J. McNally1 Jean-Robert Brisson1 James A. Mullen1 David R. McMullin1 Harold C. Jarrell1 John W. Austin2 John F. Kelly1 and Susan M. Logan1 1 NRC-Institute for BiologicalSciences Ottawa Canada 2 Bureau of MicrobialHazards HFPB Health Canada Sir Frederick G. Banting Research Centre Ottawa Canada Keywords Clostridium botulinum flagellin legionaminic acid protein glycosylation Correspondence S. M. Logan Institute for Biological Sciences National Research Council Room 3037 100 Sussex Drive Ottawa ON K1A0R6 Canada Fax 1 613 952 9092 Tel 1 613 990 0839 E-mail Received 6 June 2008 revised 3 July 2008 accepted 7 July 2008 doi Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417 Da in O-linkage. Bio-informatic analysis of available C. botulinum genomes identified a flagellar glycosylation island containing homologs of genes recently identified in Campylobacter coli that have been shown to be responsible for the biosynthesis of legionaminic acid derivatives. Structural characterization of the carbohydrate moiety was completed utilizing both MS and NMR spectroscopy and it was shown to be a novel legionaminic acid derivative 7-acetamido-5- N-methyl-glutam-4-yl -amino-3 5 7 9-tetradeoxy-D-glycero-a-D-galacto-nonulosonic acid aLeg5GluNMe7Ac . Electron transfer dissociation MS with and without collision-activated dissociation was utilized to map seven sites of O-linked glycosylation eliminating the need for chemical derivatization of tryptic peptides prior to analysis. Marker ions for novel glycans as well .