title: A novel family of antimicrobial peptides from the skin of Amolops loloensis.
abstract: While conducting experiments to investigate antimicrobial peptides of amphibians living in the Yunnan-Sichuan region of southwest China, a new family of antimicrobial peptides was identified from skin secretions of the rufous-spotted torrent frog, Amolops loloensis. Members of the new peptide family named amolopins are composed of 18 amino acids with a unique sequence, for example, NILSSIVNGINRALSFFG. By BLAST search, amolopins did no show similarity to any known peptides. Among the tested microorganisms, native and synthetic peptides only showed antimicrobial activities against Staphylococcus aureus ATCC2592 and Bacillus pumilus, no effects on other microorganisms. The CD spectroscopy showed that it adopted a structure of random combined with beta-sheet in water, Tris-HCl or Tris-HCl-SDS. Several cDNAs encoding amolopins were cloned from the skin cDNA library of A. loloensis. The precursors of amolopin are composed of 62 amino acid residues including predicted signal peptides, acidic propieces, and mature antimicrobial peptides. The preproregion of amolopin precursor comprises a hydrophobic signal peptide of 22 residues followed by an 18 residue acidic propiece which terminates by a typical prohormone processing signal Lys-Arg. The preproregions of precursors are very similar to other amphibian antimicrobial peptide precursors but the mature amolopins are different from other antimicrobial peptide families. The remarkable similarity of preproregions of precursors that give rise to very different antimicrobial peptides in distantly related frog species suggests that the corresponding genes form a multigene family originating from a common ancestor.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Life Sciences College of Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
authors.forename: Aili
authors.initials: A
authors.lastname: Wang
authors.forename: Jiyuan
authors.initials: J
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Hong
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
authors.forename: Hailong
authors.initials: H
authors.lastname: Yang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yu
authors.forename: Yufang
authors.initials: Y
authors.lastname: Ma
authors.forename: Ren
authors.initials: R
authors.lastname: Lai
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D001483:Base Sequence; D003001:Cloning, Molecular; D053878:Hemolytic Agents / Q000737:chemistry / Q000494:pharmacology; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D011898:Ranidae / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*
chemical_list: D029845:Amphibian Proteins; D000890:Anti-Infective Agents; D053878:Hemolytic Agents; D010455:Peptides