title: Structure of the O-specific polysaccharide of Proteus vulgaris O15 containing a novel regioisomer of N-acetylmuramic acid, 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose.
abstract: An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus vulgaris O15 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY, and H-detected 1H,(13)C HMQC experiments. The polysaccharide was found to contain an ether of GlcNAc with lactic acid, and the following structure of the repeating unit was established:-->3)-alpha-D-GlcpNAc4(R-Lac)6Ac-(1-->2)-beta-D-GlcpA-(1-->3)-alpha-L-6dTalp2Ac-(1-->3)-beta-D-GlcpNAc-(1-->where L-6dTal and D-GlcNAc4(R-Lac) are 6-deoxy-L-talose and 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose, respectively. The latter sugar, which to our knowledge has not been hitherto found in nature, was isolated from the polysaccharide by solvolysis with anhydrous triflic acid and identified by comparison with the authentic synthetic compound. Serological studies with the Smith-degraded polysaccharide showed an importance of 2-substituted GlcA for manifesting of the immunospecificity of P. vulgaris O15.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation. perepel@ioc.ac.ru
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Torzewska
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ziolkowski
authors.forename: Sof'ya N
authors.initials: SN
authors.lastname: Senchenkova
authors.forename: Antoni
authors.initials: A
authors.lastname: Rozalski
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis; D008070:Lipopolysaccharides / Q000737:chemistry / Q000276:immunology; D008745:Methylation; D008969:Molecular Sequence Data; D009112:Muramic Acids / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D019081:O Antigens / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D011514:Proteus vulgaris / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D008070:Lipopolysaccharides; D009112:Muramic Acids; D019081:O Antigens; D011134:Polysaccharides; C430212:lipopolysaccharide, Proteus; C031651:N-acetylmuramic acid