Molecular cloning of an invertebrate goose-type lysozyme gene from Chlamys farreri, and lytic activity of the recombinant protein

摘要: Lysozyme is a widely distributed hydrolase possessing lytic activity against bacterial peptidoglycan, which enables it to protect the host pathogenic infection. In present study, cDNA of an invertebrate goose-type lysozyme (designated CFLysG) was cloned from Zhikong scallop Chlamys farreri by expressed sequence tag (EST) and rapid amplification ends (RACE) techniques. The full-length CFLysG consisted 829 nucleotides with canonical polyadenylation signal AATAAA poly(A) tail, open reading frame (ORF) 603 bp encoding polypeptide 200 amino acid residues predicted molecular weight 21.92 kDa theoretical isoelectric point 7.76. high similarity (g-type) lysozymes in vertebrate indicated that should be counterpart g-type family, suggested origin preceded emergence urochordates even deuterostomes. Similar most lysozymes, possessed all conserved features critical for fundamental structure function such as three catalytic (Glu 82, Asp 97, 108). By Northern blot analysis, mRNA transcript found abundantly tissues gills, hepatopancreas gonad, weakly haemocytes mantle, while undetectable adductor muscle. These results could possess combined both immune digestive adaptive lysozymes. To gain insight into vitro activities CFLysG, mature peptide coding region Pichia pastoris heterogeneous expression. Recombinant showed inhibitive effect on growth Gram-positive Gram-negative bacteria more potent bacteria, involvement innate immunity C. farreri.