title: Structure determination of Streptococcus suis serotype 14 capsular polysaccharide.
abstract: The capsular polysaccharide (CPS) of Streptococcus suis serotype 14 was purified, chemically modified, and characterized. Sugar and absolute configuration analyses gave the following CPS composition: D-Gal, 3; D-Glc, 1; D-GlcNAc, 1; D-Neu5Ac, 1. The Sambucus nigra lectin, which recognizes the Neu5Ac(α2-6)Gal/GalNAc sequence, showed binding to the native CPS. Sialic acid was found to be terminal, and the CPS was quantitatively desialylated by mild acid hydrolysis. It was also submitted to periodate oxidation followed by borohydride reduction and Smith degradation. Sugar and methylation analyses, (1)H and (13)C nuclear magnetic resonance, and mass spectrometry of the native CPS or of its specifically modified products allowed to determine the repeating unit sequence: [6)[Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)]Gal(β1-3)Gal(β1-4)Glc(β1-](n). S. suis serotype 14 CPS has an identical sialic acid-containing side chain as serotype 2 CPS, but differs by the absence of rhamnose in its composition. The same side chain is also present in group B Streptococcus type Ia CPS, except that in the latter sialic acid is 2,3- rather than 2,6-linked to the following galactose. A correlation between the S. suis CPS sequence and genes of the serotype 14 cps locus encoding putative glycosyltransferases and polymerase responsible for the biosynthesis of the repeating unit is proposed.
authors.affiliation: Food Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Hyacinthe, QC J2S 8E3, Canada. marie-rose.vancalsteren@agr.gc.ca
authors.forename: Marie-Rose
authors.initials: MR
authors.lastname: Van Calsteren
authors.forename: Fleur
authors.initials: F
authors.lastname: Gagnon
authors.forename: Cynthia
authors.initials: C
authors.lastname: Calzas
authors.forename: Guillaume
authors.initials: G
authors.lastname: Goyette-Desjardins
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Okura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takamatsu
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Mariela
authors.initials: M
authors.lastname: Segura
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D056426:Genetic Loci; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D037121:Plant Lectins / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D011485:Protein Binding; D054788:Ribosome Inactivating Proteins / Q000737:chemistry; D012794:Sialic Acids / Q000032:analysis; D017011:Streptococcus suis / Q000737:chemistry* / Q000235:genetics
chemical_list: D037121:Plant Lectins; D011135:Polysaccharides, Bacterial; C050600:Sambucus nigra lectins; D012794:Sialic Acids; D054788:Ribosome Inactivating Proteins