title: Structure of the polysaccharide chain of the lipopolysaccharide from Flexibacter maritimus.
abstract: Flexibacter maritimus, a Gram-negative bacterium, is a fish pathogen responsible for disease in finfish species and a cause of cutaneous erosion disease in sea-caged salmonids. For the development of serology based diagnostics, protective vaccines, and a study of pathogenesis, the structural analysis of the lipopolysaccharide (LPS) produced by the bacterium has been undertaken. We now report that an acidic O-specific polysaccharide, obtained by mild acid degradation of the F. maritimus LPS was found to be composed of a disaccharide repeating unit built of 2-acetamido-3-O-acetyl-4-[(S)-2-hydroxyglutar-5-ylamido]-2,4,6-trideoxy-beta-glucose and 5-acetamido-7-[(S)-3-hydroxybutyramido]-8-amino-3,5,7,8,9-pentadeoxynonulopyranosonic acid (Sug) having the structure: The configuration of the C-2-C-7 fragment of the latter monosaccharide (B) was assigned beta-manno; however, the configuration at C-8 could not be established. NMR data indicate that the two monosaccharides have opposite absolute configurations. The repeating unit includes a linkage via a (S)-2-hydroxyglutaric acid residue, reported here for the first time as a component of a bacterial polysaccharide. The LPS was also found to contain a minor amount of a disaccharide beta-Sug-(2-3)-l-Rha, isolated from the products of the acidic methanolysis of the LPS.
authors.affiliation: Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Leann L
authors.initials: LL
authors.lastname: MacLean
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Crump
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Perry
authors.forename: William W
authors.initials: WW
authors.lastname: Kay
mesh_terms: D001438:Bacteroidaceae / Q000737:chemistry* / Q000276:immunology; D002236:Carbohydrate Conformation; D004187:Disaccharides / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004187:Disaccharides; D008070:Lipopolysaccharides; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial