title: Molecular Characterization and Phylogenetic Analysis of Novel Isoform of Anti-lipopolysaccharide Factor from the Mantis Shrimp, Miyakea nepa.
abstract: Anti-lipopolysaccharide factor (ALF) is a cationic anti-microbial peptide representing humoral defence system exhibiting a diverse spectrum of activity against microbial pathogens, including gram-negative and gram-positive bacteria, fungi, parasites and viruses. In this study, we identified and characterized a novel ALF homologue (MnALF) encoding cDNA sequence from the haemocytes of stomatopod mantis shrimp Miyakea nepa. The deduced peptide of MnALF encoded for a 123-amino acid peptide with a 25-residue signal peptide containing selenocysteine followed by a highly cationic mature peptide comprised of a putative LPS-binding domain flanked by two cysteine residues. BLAST analysis of MnALF showed that it exhibits identity to crustacean and limulid ALFs. The mature peptide of MnALF has a net charge of +7 and predicted molecular weight of 10.998 kDa with a theoretical isoelectric point (pI) of 9.93. Spatial structure of MnALF comprises three α-helices packed against a four-stranded β-sheet of which two were linked by a disulphide bond to form an amphipathic loop similar to the structure of Penaeus monodon, ALF-Pm3. All these features suggest that MnALF could play an imperative role in the innate defence mechanism of M. nepa. To our knowledge, this study accounts for the first report of an anti-microbial peptide from the order stomatopoda.
authors.affiliation: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Sruthy
authors.affiliation: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
authors.forename: E R
authors.initials: ER
authors.lastname: Chaithanya
authors.affiliation: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
authors.forename: Naveen
authors.initials: N
authors.lastname: Sathyan
authors.affiliation: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
authors.forename: Aishwarya
authors.initials: A
authors.lastname: Nair
authors.affiliation: National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, 682 016, Kerala, India.
authors.forename: Swapna P
authors.initials: SP
authors.lastname: Antony
authors.affiliation: National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, 682 016, Kerala, India.
authors.forename: I S Bright
authors.initials: IS
authors.lastname: Singh
authors.affiliation: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India. rosammap@gmail.com.
authors.forename: Rosamma
authors.initials: R
authors.lastname: Philip
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000302:isolation & purification*; D001483:Base Sequence; D004247:DNA; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000737:chemistry* / Q000276:immunology; D010802:Phylogeny; D011487:Protein Conformation; D020033:Protein Isoforms; D021382:Protein Sorting Signals; D016415:Sequence Alignment
chemical_list: D023181:Antimicrobial Cationic Peptides; D008070:Lipopolysaccharides; D020033:Protein Isoforms; D021382:Protein Sorting Signals; D004247:DNA
keywords: Anti-lipopolysaccharide factor; Anti-microbial peptides; Miyakea nepa; Selenocysteine; Stomatopod crustacean