title: Structural elucidation of the O-antigenic polysaccharide from enterohemorrhagic (EHEC) Escherichia coli O48:H21.
abstract: The structure of the antigenic O-polysaccharide (O-PS) of the lipopolysaccharide (LPS) produced by the enterohemorrhagic strain of Escherichia coli O48:H21 (EHEC) has been elucidated. The O-PS obtained by mild acid hydrolysis of the LPS had [alpha]D +95 (water) and was composed of L-rhamnose (L-Rha), D-galactose (D-Gal), 2-amino-2-deoxy-D-glucose (D-GlcN), 2-amino-2-deoxy-D-galactose (D-GalN), and D-galacturonic acid (D-GalA) (1:1:1:1:1). From the results of methylation analysis, mass spectrometry, 2D NMR, and DOC-PAGE, the O-PS was shown to be a high molecular mass polymer of a repeating pentasaccharide unit having the structure: [structure: see text]. The D-Gal pA non-reducing end groups in the O-PS were partially O-acetylated (approximately 30%) at the O-2 and O-3 positions and the degree of acetylation was variable from batch to batch cell production.
authors.affiliation: Institute for Biological Sciences, National Research Council, Ottawa, Canada K1A OR6.
authors.forename: Leann L
authors.initials: LL
authors.lastname: MacLean
authors.forename: Ann C
authors.initials: AC
authors.lastname: Webb
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Perry
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D019453:Escherichia coli O157 / Q000737:chemistry*; D007202:Indicators and Reagents; D008070:Lipopolysaccharides / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial