title: Functional Characterization of a c-type Lysozyme from Indian Shrimp Fenneropenaeus indicus.
abstract: Lysozyme gene from Fenneropenaeus indicus was cloned, expressed in Escherichia coli and characterized. The cDNA consists of 477 base pairs and encodes amino acid sequence of 159 residues. F. indicus lysozyme had high identity (98%) with Fenneropenaeus merguiensis and Fenneropenaeus chinensis and exhibits low to moderate identities with lysozymes of other invertebrates and vertebrates. This lysozyme is presumed to be chicken types as it possesses two catalytic and eight cysteine residues that are conserved across c-type lysozymes and a c-terminal extension, which is a characteristic of lysozymes from marine invertebrates. Further, the antimicrobial properties of the recombinant lysozyme from F. indicus were determined in comparison with recombinant hen egg white lysozyme. This exhibited high activity against a Gram-negative pathogenic bacterium Salmonella typhimurium and two fungal strains Pichia pastoris and Saccharomyces cerevisiae in turbidimetric assay. Distribution of lysozyme gene and protein in tissues of shrimps infected with white spot syndrome virus revealed that the high levels of lysozyme are correlated with low and high viral load in abdominal muscle and tail, respectively. In conclusion, lysozyme from F. indicus has a broad spectrum of antimicrobial properties, which once again emphasizes its role in shrimp innate immune response.
authors.affiliation: Centre for Biotechnology, Anna University, Chennai, 600025, Tamil Nadu, India, karthikbio.v@gmail.com.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Karthik
authors.forename: Vijayan
authors.initials: V
authors.lastname: Kamalakannan
authors.forename: Ancy
authors.initials: A
authors.lastname: Thomas
authors.forename: Naduvilamuriparambu Saidumuhammed
authors.initials: NS
authors.lastname: Sudheer
authors.forename: Issac S Bright
authors.initials: IS
authors.lastname: Singh
authors.forename: Rangarajan Badri
authors.initials: RB
authors.lastname: Narayanan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D003001:Cloning, Molecular; D005658:Fungi / Q000187:drug effects; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D033561:Penaeidae / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment; D012758:Shellfish / Q000032:analysis; D046848:White spot syndrome virus 1 / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D009113:Muramidase