Identification and characterization of a novel gene-encoded antioxidant peptide obtained from amphibian skin secretions

Abstract

Amphibian skin is known to secrete gene-encoded antioxidant peptides of small molecular weight, which play important roles in host defense. However, recognition of such peptides is still in its infancy. Here, we discovered a novel gene-encoded antioxidant peptide (named OM-GF17) from skin secretions of amphibian species, Odorrana margaretae. Produced by the post-translational processing of a 61-residue prepropeptide, the amino acid sequence of OM-GF17 was 'GFFKWHPRCGEEHSMWT', with a molecular mass of 2135.7 Da. Functional analysis revealed that OM-GF17 scavenged ABTS⁺, DPPH, NO and decreased iron oxidation. Our results also implied that five amino acid residues, including Cys, Pro, Met, Trp, and Phe, be related to the antioxidant activity of OM-GF17. Furthermore, OM-GF17 did not exhibit direct microbe-killing activity. This novel gene-encoded antioxidant peptide could help in the development of new antioxidant agents and increase our understanding of the biological functions of amphibian skin.

Keywords:

• Odorrana margaretae
• OM-GF17
• antioxidant peptide
• molecular basis

Disclosure statement

The authors declare no competing commercial interests in relation to this work.

Funding

This work was supported by grants from the Chinese National Natural Science Foundation (31460571, 81760648, 31660244, 81500983, and 31670776) and Yunnan Applied Basic Research Project (2017FB035).