title: The chemical structure of the lipid A component of lipopolysaccharides from Vibrio cholerae.
abstract: The chemical structure of the lipid A component of the lipopolysaccharide from Vibrio cholerae 95R was studied. After sequential degradation a reduced D-glucosamine disaccharide was isolated from lipid A and, after permethylation, shown by combined gas-liquid chromatography/mass spectrometry to be beta 1,6-linked. The disaccharide is substituted with a phosphate group, ester-bound to the non-reducing glucosamine (GlcN) residue and a pyrophosphorylethanolamine group (PP-Etn) linked to C-1 of the reducing glucosamine residue. This backbone structure is shown in the following formula: P-GlcN(beta 1-6)GlcN-1-PP-Etn. The amino groups of the glucosamine disaccharide are substituted by D-3-hydroxytetradecanoic acid; tetradecanoic, hexadecanoic and a D-3-O-(D-3-hydroxydodecanoyl)-dodecanoic acid residue are linked to hydroxyl groups. A similar fatty acid composition was detected in lipopolysaccharides from Inaba, Ogawa and NAG strains of V. cholerae.
mesh_terms: D002849:Chromatography, Gas; D004187:Disaccharides / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D008050:Lipid A / Q000032:analysis*; D008070:Lipopolysaccharides / Q000032:analysis*; D013058:Mass Spectrometry; D014734:Vibrio cholerae / Q000032:analysis*
chemical_list: D004187:Disaccharides; D005227:Fatty Acids; D008050:Lipid A; D008070:Lipopolysaccharides