title: Aldobiouronic acid domains in Helicobacter pylori.
abstract: Helicobacter pylori cell-surface glycans exert strong influences in host-microbe interplays and define the strain's immunological signature. Envisaging the development of a carbohydrate-based vaccine against the gastroduodenal pathogen H. pylori, several clinical isolates are being screened for their cell-surface glycan profile. The present work concerns H. pylori clinical specimen PTAV79 that abundantly expressed amylose-like glycans. These polysaccharides were isolated in glycan-rich fractions resultant from phenol-water extractions and purified by Bio-Gel P2. Structural studies showed that the glycans are linked to glycerol and present aldobiouronic acid domains composed of [→3)-α-D-GlcA-(1→4)-α-D-Glc-(1→] repeating units. The amylose domains were constituted by an average of 19 Glc residues and the acidic moieties had an average number of 10 aldobiouronic acid repeating units. These polysaccharides were isolated in fractions that, although hydrophilic, were rich in stearic acid, strongly suggesting that they are present as glycerolipids anchored to cell-surface.
authors.affiliation: QOPNA, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: José A
authors.initials: JA
authors.lastname: Ferreira
authors.forename: M Rosário M
authors.initials: MR
authors.lastname: Domingues
authors.forename: Ana
authors.initials: A
authors.lastname: Reis
authors.forename: Ceu
authors.initials: C
authors.lastname: Figueiredo
authors.forename: Mário A
authors.initials: MA
authors.lastname: Monteiro
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Coimbra
mesh_terms: D005936:Glucans / Q000737:chemistry; D016480:Helicobacter pylori / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014574:Uronic Acids / Q000737:chemistry*
chemical_list: D005936:Glucans; D008070:Lipopolysaccharides; D014574:Uronic Acids