title: Characterization of the core oligosaccharide and the O-antigen biological repeating unit from Halomonas stevensii lipopolysaccharide: the first case of O-antigen linked to the inner core.
abstract: A novel core structure among bacterial lipopolysaccharides (LPS) that belong to the genus Halomonas has been characterized. H. stevensii is a moderately halophilic microorganism, as are the majority of the Halomonadaceae. It brought to light the pathogenic potential of this genus. On account of their role in immune system elicitation, elucidation of LPS structure is the mandatory starting point for a deeper understanding of the interaction mechanisms between host and pathogen. In this paper we report the structure of the complete saccharidic portion of the LPS from H. stevensii. In contrast to the finding that the O-antigen is usually covalently linked to the outer core oligosaccharide, we could demonstrate that the O-polysaccharide of H. stevensii is linked to the inner core of an LPS. By means of high-performance anion-exchange chromatography with pulsed amperometric detection we were able to isolate the core decasaccharide as well as a tridecasaccharide constituted by the core region plus one O-repeating unit after alkaline degradation of the LPS. The structure was elucidated by one- and two-dimensional NMR spectroscopy, ESI Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry, and chemical analysis.
authors.affiliation: Dipartimento di Chimica Organica e Biochimica, Università Federico II di Napoli, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italia.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Pieretti
authors.forename: Sara
authors.initials: S
authors.lastname: Carillo
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.forename: Kwang Kyu
authors.initials: KK
authors.lastname: Kim
authors.forename: Keun Chul
authors.initials: KC
authors.lastname: Lee
authors.forename: Jung-Sook
authors.initials: JS
authors.lastname: Lee
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: D020632:Halomonas / Q000737:chemistry* / Q000276:immunology; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D019081:O Antigens / Q000737:chemistry* / Q000276:immunology; D009844:Oligosaccharides / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D019081:O Antigens; D009844:Oligosaccharides