title: Identification of the common antigenic determinant shared by Streptococcus pneumoniae serotypes 35A and 20 capsular polysaccharides--structural analysis of the Streptococcus pneumoniae serotype 35A capsular polysaccharide.
abstract: The specific polysaccharide antigen of Streptococcus pneumoniae serotype 35A was shown, by a combination of one- and two-dimensional NMR methods and chemical analyses, to be a high-molecular-mass polymer composed of D-galactose, D-glucose, mannitol, and phosphate (3:1:1:1). The pentasaccharide repeating unit is polymerized through phosphate diester linkages to give the structure, [formula in text] O-Acetyl substituents are present at positions 5 and 6 of the 3)-beta-D-Galf residue and at position 2 of the 6)-beta-D-Galf residue. The capsular polysaccharides of S. pneumoniae serotypes 20 and 35A both contain the disaccharide unit -->3)-beta-D-Galf-(1-->3)-beta-D-Glcp-(1--> which is the probable structural determinant responsible for the serological cross reactivity of the two polysaccharides.
authors.affiliation: Institute for Biological Sciences, National Research Council of Canada, Ottawa ON.
authors.forename: L M
authors.initials: LM
authors.lastname: Beynon
authors.forename: J C
authors.initials: JC
authors.lastname: Richards
authors.forename: M B
authors.initials: MB
authors.lastname: Perry
mesh_terms: D016667:Bacterial Capsules / Q000737:chemistry / Q000276:immunology*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003429:Cross Reactions; D004187:Disaccharides / Q000032:analysis / Q000276:immunology; D000939:Epitopes / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000276:immunology*
chemical_list: D004187:Disaccharides; D000939:Epitopes; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; C110031:capsular polysaccharide 35A