Isolation and characterization of a novel antimicrobial peptide from Bufo bufo gargarizans

Abstract

A novel antimicrobial peptide was isolated from Bufo bufo gargarizans, an Asian toad, using heparin chromatography and reversed-phase HPLC. The antimicrobial peptide killed Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas putida, Salmonella typhimurium, Candida albicans. The complete amino acid sequence of the antimicrobial peptide was, Ala-Gly-Arg-Gly-Lys-Gln-Gly-Gly-Lys-Val-Arg-Ala-Lys-Ala-Lys-Thr-Arg-Ser-Ser- Arg-Ala-Gly-Leu-Gln-Phe-Pro-Val-Gly-Arg-Val-His-His-Leu-Leu-Leu-Leu-Lys-Gly- Asn-Tyr. The peptide has no homology with other known antimicrobial peptides except the human histone H2A protein to which the antimicrobial peptide is identical in 35 of 40 amino-terminal residues. We believe that this is a new antimicrobial peptide which does not belong to any other known classes of antimicrobial peptides.