| Sujet | 13C-NMR; 1H-NMR; acids; antibodies; bacterial; binding; capsular polysaccharide; carbohydrate conformation; carbohydrate sequence; chemistry; d-glucose; epitope; form; group B streptococcus; immunochemical characterization; immunology; indicators and reagents; isolation & purification; laboratories; magnetic resonance spectroscopy; methylation; methylation analysis; models, molecular; molar; molecular sequence data; NMR analysis; polysaccharides; polysaccharides, bacterial; repeating unit; residues; sialic acid; streptococcus; streptococcus agalactiae; structure; sugars; support, non-U. S. Gov't; support, U.S. Gov't, P.H.S.; unit |
|---|
| Résumé | The type V capsular polysaccharide of group B Streptococcus has been isolated and purified, and its repeating unit structure determined. The native type V polysaccharide contains D-glucose, D-galactose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in a molar ratio of 3:2:1:1. Methylation analysis and 1H NMR and 13C NMR analysis of the native type V polysaccharide and of its specifically degraded products permitted the determination of the repeating unit structure of the type V polysaccharide: [formula: see text] The type V polysaccharide has certain structural features in common with other group B streptococcal capsular polysaccharides but is antigenically distinct: no immunologic cross-reactivity was observed between type V and types Ia, Ib, II, III, or IV polysaccharides. Studies of antibody binding to the partially degraded forms of the type V polysaccharide indicated that the native epitope is complex, involving most if not all of the sugar residues of the repeating unit |
|---|
