title: The structure of the antigenic polysaccharide produced by Eubactrium saburreum T15.
abstract: The antigenic polysaccharide was obtained from the cell wall of Eubacterium saburreum strain T15 by trypsin digestion followed by gel permeation and ion-exchange chromatography. Its structure was determined using acid hydrolysis, methylation analysis, and 1D and 2D NMR spectroscopy. It contained L-threo-pent-2-ulose (Xul), D-fucose (Fuc), and D-glycero-D-galacto-heptose (Hep) in 2:3:3 ratio. Methylation analysis indicated an octasaccharide repeating-unit containing five branches. The 1H and 13C signals in NMR spectra of the sugar residues were assigned by COSY, HOHAHA, and HMQC 2D experiments, and the sequence of sugar residues in the repeating unit was determined by NOESY and HMBC experiments. The polysaccharide also contains two O-acetyl groups in the repeating unit, located on the Hep residue. The repeating structure can be written as: [see text for equation]. This is a novel structure in bacterial cell-wall polysaccharides from Gram-positive bacteria.
authors.affiliation: Department of Oral Health Science, Division of Oral Ecology in Health and Infection, Course for Oral Life Science, Niigata University Graduate School of Medical and Dental Sciences, Gakkocho-dori 2, Niigata 951-8514, Japan. sa-naomi@dent.niigata-u.ac.jp
authors.forename: Naomi
authors.initials: N
authors.lastname: Sato
authors.forename: Futoshi
authors.initials: F
authors.lastname: Nakazawa
authors.forename: Teiichiro
authors.initials: T
authors.lastname: Ito
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hoshino
authors.forename: Etsuro
authors.initials: E
authors.lastname: Hoshino
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry; D005051:Eubacterium / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D011135:Polysaccharides, Bacterial