title: Identification and structure-activity relationship of an antimicrobial peptide of the palustrin-2 family isolated from the skin of the endangered frog Odorrana ishikawae.
abstract: Recently, we identified nine novel antimicrobial peptides from the skin of the endangered anuran species, Odorrana ishikawae, to assess its innate immune system. In this study an additional antimicrobial peptide was initially isolated based on antimicrobial activity against Escherichia coli. The new antimicrobial peptide belonging to the palustrin-2 family was named palustrin-2ISb. It consists of 36 amino acid residues including 7 amino acids C-terminal to the cyclic heptapeptide Rana box domain. The peptide's primary structure suggests a close relationship with the Chinese odorous frog, Odorrana grahami. The cloned cDNA encoding the precursor protein contained a signal peptide, an N-terminal acidic spacer domain, a Lys-Arg processing site and the C-terminal precursor antimicrobial peptide. It also contained 3 amino acid residues at the C-terminus not found in the mature peptide. Finally, the antimicrobial activities against four microorganisms (E. coli, Staphylococcus aureus, methicillin-resistant S. aureus and Candida albicans) were investigated using several synthetic peptides. A 29 amino acid truncated form of the peptide, lacking the 7 amino acids C-terminal to the Rana box, possessed greater antimicrobial activities than the native structure.
authors.affiliation: Section of Life Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Iwakoshi-Ukena
authors.forename: Genya
authors.initials: G
authors.lastname: Okada
authors.forename: Aiko
authors.initials: A
authors.lastname: Okimoto
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Fujii
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sumida
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ukena
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011898:Ranidae / Q000033:anatomy & histology / Q000276:immunology*; D016415:Sequence Alignment; D012867:Skin / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides