title: Evidence in oyster of a plasma extracellular superoxide dismutase which binds LPS.
abstract: We have characterized in the oyster Crassostrea gigas an extracellular superoxide dismutase (Cg-EcSOD) which appears to bind lipopolysaccharides (LPS). The protein has been purified from the oyster plasma and identified as a Cu/ZnSOD according to its N-terminal sequencing and biological activity. Cg-EcSOD expression and synthesis are restricted to hemocytes as revealed by in situ hybridization and immunocytochemistry. Cg-EcSOD-expressing hemocytes were seen in blood circulation, in connective tissues, and closely associated to endothelium blood vessels. Cg-EcSOD presents in its amino acid sequence a LPS-binding motif found in the endotoxin receptor CD14 and we show that the protein displays an affinity to Escherichia coli bacteria and with LPS and Lipid A. Additionally, an RGD motif known to be implicated in the association to membrane integrin receptor is present in the amino acid sequence. The purified Cg-EcSOD was shown to bind to oyster hemocytes and to be immunocolocalized with a beta-integrin-like receptor.
authors.affiliation: UMR 5171, CNRS-UMII-IFREMER, Génome Population Interactions Adaptation, Université de Montpellier II, 2 Place Eugène Bataillon, CC80, 34095 Montpellier Cedex 5, France.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gonzalez
authors.forename: Bernard
authors.initials: B
authors.lastname: Romestand
authors.forename: Julie
authors.initials: J
authors.lastname: Fievet
authors.forename: Arnaud
authors.initials: A
authors.lastname: Huvet
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Lebart
authors.forename: Yannick
authors.initials: Y
authors.lastname: Gueguen
authors.forename: Evelyne
authors.initials: E
authors.lastname: Bachère
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D004926:Escherichia coli / Q000378:metabolism*; D045604:Extracellular Fluid / Q000201:enzymology*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010125:Ostreidae / Q000201:enzymology*; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000097:blood* / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D013482:Superoxide Dismutase