title: Novel antibacterial peptides from the skin secretion of the Indian bicoloured frog Clinotarsus curtipes.
abstract: HPLC elution profile and MALDI TOF MS analysis of electro-stimulated skin secretion of the Indian Ranid frog Clinotarsus curtipes of the Western Ghats confirmed the presence of multiple peptides. Peptides eluted out of the C18 column at higher hydrophobic solvent region showed antibacterial activity against diverse bacterial strains, including the clinical isolates of V. cholerae and methicillin resistant Staphylococcus aureus (MRSA). Peptidomic analysis of the most potent chromatographic effluent fraction identified five novel peptide amides having sequence homology with brevinin family. These peptides are named as brevinin1CTcu1 (B1CTcu1) to brevinin1CTcu5 (B1CTcu5). Peptide B1CTcu1 is non-haemolytic while the others are haemolytic in nature but all elicited potential antibacterial activity. B1CTcu5 is a twenty-one residue peptide amide having proline hinge region in the middle and the typical C-terminal intramolecular disulfide-bridged hepta peptide domain (Rana box) that is present in most of the brevinin peptides. Analysis of their killing kinetics with E. coli and S. aureus and the ability to induce membrane depolarization proved that these are two independent events. These novel multifunctional peptides play an important role to protect C. curtipes from invading pathogenic microorganisms present in the environment.
authors.affiliation: Chemical Biology Laboratory, Dept of Molecular Medicine, Rajiv Gandhi Centre for Biotechnology, Jagathy, Thiruvananthapuram 695014, Kerala, India.
authors.forename: Parvin
authors.initials: P
authors.lastname: Abraham
authors.affiliation: Chemical Biology Laboratory, Dept of Molecular Medicine, Rajiv Gandhi Centre for Biotechnology, Jagathy, Thiruvananthapuram 695014, Kerala, India.
authors.forename: Sanil
authors.initials: S
authors.lastname: George
authors.affiliation: Chemical Biology Laboratory, Dept of Molecular Medicine, Rajiv Gandhi Centre for Biotechnology, Jagathy, Thiruvananthapuram 695014, Kerala, India. Electronic address: kskumar@rgcb.res.in.
authors.forename: K Santhosh
authors.initials: KS
authors.lastname: Kumar
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004558:Electric Stimulation; D004912:Erythrocytes / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D006461:Hemolysis / Q000187:drug effects; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011817:Rabbits; D011898:Ranidae; D012867:Skin / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D014734:Vibrio cholerae / Q000187:drug effects / Q000254:growth & development
chemical_list: D029845:Amphibian Proteins; D023181:Antimicrobial Cationic Peptides; C078413:brevinin-1 protein, Rana
keywords: Amphibian skin secretion; B1CTcu1–B1CTcu5; Clinotarsus curtipes; Host defense peptides (HDPs); Western Ghats