title: Lipopolysaccharides of Helicobacter pylori serogroups O:3 and O:6--structures of a class of lipopolysaccharides with reference to the location of oligomeric units of D-glycero-alpha-D-manno-heptose residues.
abstract: Lipopolysaccharides (LPS) from antigenically different strains assigned to serogroups O:3 and O:6 of Helicobacter pylori were isolated as water-soluble material of high Mr and as water-insoluble gels of low Mr. Chemical and spectroscopic analyses of the soluble LPS and oligosaccharides liberated from the water-insoluble gels led to proposed structures with Lewis (Le) antigen determinants terminating regular repeating units of different types, linked in turn to inner core regions of invariable structure. The O:6 LPS has two populations of related molecules with chains of 3-linked D-glycero-alpha-D-manno-heptose residues similar to those in the MO19 strain, one with and the other without a single terminal Lewis (Le(y)) epitope. In contrast, in the O:3 LPS, Lewis (Le(x) and Le(y)) epitopes terminate a partially fucosylated N-acetyllactosaminoglycan, but a heptan chain similar to that in the O:6 LPS was shown to connect the outer chains to the inner core. These LPS provide examples of the molecular mimicry of cell-surface glycoconjugates. Structural variations of LPS between strains, and differences in some aspects of structure within strains, between high Mr and low Mr LPS indicate a class of LPS whose mechanisms of biosynthesis lead to overall architectures different from those characteristic of most LPS from enteric bacteria.
authors.affiliation: Department of Chemistry, York University, Toronto, Ontario, Canada.
authors.forename: G O
authors.initials: GO
authors.lastname: Aspinall
authors.forename: M A
authors.initials: MA
authors.lastname: Monteiro
authors.forename: R T
authors.initials: RT
authors.lastname: Shaver
authors.forename: L A
authors.initials: LA
authors.lastname: Kurjanczyk
authors.forename: J L
authors.initials: JL
authors.lastname: Penner
mesh_terms: D000606:Amino Sugars / Q000737:chemistry / Q000378:metabolism; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis; D016480:Helicobacter pylori / Q000737:chemistry* / Q000276:immunology; D007983:Lewis Blood Group Antigens / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012995:Solubility
chemical_list: D000606:Amino Sugars; D002241:Carbohydrates; D007983:Lewis Blood Group Antigens; C094162:Lewis Y antigen; D008070:Lipopolysaccharides; D019081:O Antigens; D011134:Polysaccharides; C039448:lactosaminoglycan