Identification of cell-surface mannans in a virulent Helicobacter pylori strain.
With the intent of contributing to a carbohydrate-based vaccine against the gastroduodenal pathogen, Helicobacter pylori, we report here the structure of cell-surface mannans obtained from a virulent strain. Unlike other wild-type strains, this strain was found to express in good quantities this polysaccharide in vitro. Structural analysis revealed a branched mannan formed by a backbone of alpha-(1-->6)-linked mannopyranosyl residues with approximately 80% branching at the O-2 position. The branches were composed of O-2-linked Man residues in both alpha- and beta-configurations: [abstract: see text]. In addition, this strain also expressed cell-surface emblematic H. pylori lipopolysaccharides (LPS) containing partially fucosylated polyLacNAc O-chains. Affinity assays with polymyxin-B and concanavalin A revealed no association between the mannan and the LPS. The described mannans may be implicated in the mediation of host-microbial interactions and immunological modulation.
Departamento de Química, Universidade de Aveiro, Aveiro, Portugal.
José A
JA
Ferreira
Nuno F
NF
Azevedo
Maria João
MJ
Vieira
Céu
C
Figueiredo
Brian J
BJ
Goodfellow
Mario A
MA
Monteiro
Manuel A
MA
Coimbra
D002240:Carbohydrate Sequence; D002846:Chromatography, Affinity; D003208:Concanavalin A / Q000737:chemistry; D016480:Helicobacter pylori / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000737:chemistry*; D008969:Molecular Sequence Data; D011112:Polymyxin B / Q000737:chemistry; D014774:Virulence
D008070:Lipopolysaccharides; D008351:Mannans; D003208:Concanavalin A; D011112:Polymyxin B