title: Structural characterization of the core region from the lipopolysaccharide of the haloalkaliphilic bacterium Halomonas alkaliantarctica strain CRSS.
abstract: Halophilic and halotolerant Gram-negative bacteria are microorganisms which thrive in high salt environments. LPS are the major components of their outer leaflet, nevertheless very little is known about the role of this molecules in the adaptation mechanisms of extremophiles. Recently we determined the O-chain repeating unit structure of the LPS from Halomonas alkaliantarctica strain CRSS, an haloalkaliphilic Gram-negative bacterium isolated from salt sediments of a saline lake in Cape Russell in Antarctic continent. The polysaccharide is constituted of the trisaccharidic repeating unit: →3)-β-l-Rhap-(1→4)-α-l-Rhap-(1→3)-α-l-Rhap-(1→. In this paper we report the complete core LPS structure from this bacterium. The LPS was hydrolyzed both under mild acid and strong alkaline conditions. The MALDI spectra showed the presence of two glycoforms. The most abundant was recovered after HPAEC purification of the alkaline hydrolyzed product and was characterized by means of 2D-NMR spectroscopy. A comparison of the MALDI-PSD spectra of the two glycoforms suggested that the branched heptose was not stoichiometrically substituted.
authors.affiliation: Dipartimento di Chimica Organica e Biochimica, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia 4, 80126 Napoli, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Pieretti
authors.forename: Sara
authors.initials: S
authors.lastname: Carillo
authors.forename: Barbara
authors.initials: B
authors.lastname: Nicolaus
authors.forename: Annarita
authors.initials: A
authors.lastname: Poli
authors.forename: Rosa
authors.initials: R
authors.lastname: Lanzetta
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Parrilli
authors.forename: Maria Michela
authors.initials: MM
authors.lastname: Corsaro
mesh_terms: D002240:Carbohydrate Sequence; D020632:Halomonas / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D008969:Molecular Sequence Data
chemical_list: D008070:Lipopolysaccharides