Anti-infection Peptidomics of Amphibian Skin

Abstract

Peptidomics and genomics analyses were used to study an anti-infection array of peptides of amphibian skin. 372 cDNA sequences of antimicrobial peptides were characterized from a single individual skin of the frog Odorrana grahami that encode 107 novel antimicrobial peptides. This contribution almost triples the number of currently reported amphibian antimicrobial peptides. The peptides could be organized into 30 divergent groups, including 24 novel groups. The diversity in peptide coding cDNA sequences is, to our knowledge, the most extreme yet described for any animal. The patterns of diversification suggest that point mutations as well as insertion, deletion, and "shuffling" of oligonucleotide sequences were responsible for the diversity. The diversity of antimicrobial peptides may have resulted from the diversity of microorganisms. These diverse peptides exhibited both diverse secondary structure and "host defense" properties.

Antimicrobial peptides from amphibians

“…Amidation is a process of C-terminal glycine oxidative decarboxylation which can prevent carboxypeptidase cutting, while providing a hydrogen bond which is required for the formation of a-helix and add positive charge (33), which could be responsible for the enhancement of the antimicrobial activity of AMP (46). This phenomenon is validated by AMPs such as brevinin-1, nigrocin and palustrin (24,47).…”

“…Li et al (24) combined peptidomics and genomics analyses to study an array of antiinfection peptides from amphibian skins. In total, 372 cDNA sequences of AMPs were characterized from a single individual skin of the frog Odorrana grahami that encode 107 novel antimicrobial peptides.…”

“…AMPs are almost exclusively found in Anura, less found in Caudata. More than 200 AMPs were isolated from Ascaphidae, Bombinatoridae, Hylidae, Hyperoliidae, Leptodactylidae, Myobatrachidae, Pipidae and Ranidae (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32).…”

Host defense peptides in skin secretions of Odorrana tiannanensis: Proof for other survival strategy of the frog than merely anti-microbial

“…Odorrana tiannanensis, a characteristic species of China, is mainly found distributed in Hainan and Yunnan provinces of China. Previous work by Li et al purified and characterized 107 novel AMPs belonging to 30 different families, including 24 novel families from Odorrana grahami [9]. Totally 372 different cDNAs encoding these anti-microbial peptides were identified in that work.…”

“…Besides, there are usually more than one anti-microbial peptide families in a single amphibian species. Most of the AMPs, 10e50 residues in length, have a common highly conserved N-terminal preproregion, followed by a markedly different C-terminal domain that corresponds to mature AMPs [6,7,9]. Functionally, different amphibian antimicrobial peptides have different anti-microbial spectrum.…”