title: Biochemical and proteomic characterisation of haemolymph serum reveals the origin of the alkali-labile phosphate (ALP) in mussel (Mytilus galloprovincialis).
abstract: Mollusc haemolymph proteins are known to play several important physiological roles in the immune system, heavy metal transport and the tissue distribution of lipophilic compounds. In this study, we analysed acetone-extracted proteins from mussel haemolymph by one- and two-dimensional gel electrophoresis. The proteins were identified by comparing mass spectrometry data with the invertebrate EST database, allowing us to establish the mussel haemolymph serum proteome. Extrapallial protein (EP) precursor represents the most abundant serum protein; astacin and CuZn superoxide dismutase were also detected. Slight contamination from muscle proteins, due to the sampling method, was also found. No differences were observed in the profiles obtained for male and female serum proteins. One aspect of interest was the previously reported finding that alkali-labile phosphate (ALP) from haemolymph serum may be representative of vitellogenin (vtg)-like protein content in the circulatory fluid of molluscs. In our analysis of mussel haemolymph serum, vitellogenin-like proteins were never found. To confirm these data, a typical methyl-tert-butyl-ether (MTBE) extraction, which is specific for vtg-like proteins, was performed, and the results of the electrophoretic analyses were compared with those obtained by acetonic precipitation. The results showed that the electrophoretic profiles are similar and that vtg-like proteins cannot be identified. Moreover, the main phosphoprotein present in female and male extracts is EP protein precursor. In addition, agarose gel electrophoresis demonstrates that high-molecular-weight forms of vtg-like proteins are not detectable.
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Oliveri
authors.affiliation: Ruder Bošković Instititute, Center for Marine Research, G. Paliaga 5, 52210 Rovinj, Croatia.
authors.forename: Lorena
authors.initials: L
authors.lastname: Peric
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Sforzini
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy; Laboratory of Biochemistry and Environmental Toxicology, ISA Chott-Mariem, 4042 Sousse, Tunisia.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Banni
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Viarengo
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Cavaletto
authors.affiliation: Department of Science and Technological Innovation, University of Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, 11, 15121 Alessandria, Italy. Electronic address: francesco.marsano@mfn.unipmn.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Marsano
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006458:Hemolymph / Q000737:chemistry*; D008969:Molecular Sequence Data; D049878:Mytilus / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis / Q000737:chemistry; D011506:Proteins / Q000032:analysis / Q000737:chemistry* / Q000145:classification; D020543:Proteome / Q000032:analysis / Q000737:chemistry*; D040901:Proteomics
chemical_list: D010710:Phosphates; D011506:Proteins; D020543:Proteome
keywords: Alkali-labile phosphate (ALP); Haemolymph serum; Mytilus galloprovincialis; Proteomics; Vitellogenin (Vtg)-like proteins