Extremely abundant antimicrobial peptides existed in the skins of nine kinds of Chinese odorous frogs.
Peptide agents are regarded as hopeful candidates to solve life-threatening resistance of pathogenic microorganisms to classic antibiotics due to their unique action mechanisms. Peptidomic and genomic investigation of natural antimicrobial peptides (AMPs) from amphibian skin secretions can provide a large amount of structure-functional information to design peptide antibiotics with therapeutic potential. In the present study, we identified a large number of AMPs from the skins of nine kinds of Chinese odorous frogs. Eighty AMPs were purified from three different odorous frogs and confirmed by peptidomic analysis. Our results indicated that post-translational modification of AMPs rarely happened in odorous frogs. cDNAs encoding precursors of 728 AMPs, including all the precursors of the confirmed 80 native peptides, were cloned from the constructed AMP cDNA libraries of nine Chinese odorous frogs. On the basis of the sequence similarity of deduced mature peptides, these 728 AMPs were grouped into 97 different families in which 71 novel families were identified. Out of these 728 AMPs, 662 AMPs were novel and 28 AMPs were reported previously in other frog species. Our results revealed that identical AMPs were widely distributed in odorous frogs; 49 presently identified AMPs could find their identical molecules in different amphibian species. Purified peptides showed strong antimicrobial activities against 4 tested microbe strains. Twenty-three deduced peptides were synthesized and their bioactivities, including antimicrobial, antioxidant, hemolytic, immunomodulatory and insulin-releasing activities, were evaluated. Our findings demonstrate the extreme diversity of AMPs in amphibian skins and provide plenty of templates to develop novel peptide antibiotics.
Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China.
Xinwang
X
Yang
Wen-Hui
WH
Lee
Yun
Y
Zhang
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002460:Cell Line; D002681:China; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004912:Erythrocytes / Q000187:drug effects; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D053878:Hemolytic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010456:Peptides, Cyclic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D011898:Ranidae; D051381:Rats; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D012867:Skin / Q000378:metabolism*
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D016166:Free Radical Scavengers; D053878:Hemolytic Agents; D007328:Insulin; D010456:Peptides, Cyclic