Researchers from the Kunming Institute of Zoology and the Chinese Academy of Sciences have identified a number of antimicrobial peptides in odorous frogs. In "Extremely Abundant Antimicrobial Peptides Existed in the Skins of Nine Kinds of Chinese Odorous Frogs," Yun Zhang, Wen-Hui Lee and Xinwang Yang report in the American Chemical Society's Journal of Proteome Research that more than 700 antimicrobial peptides were found in the nine frogs studied.
The researchers noted that frogs live in environments with abundant bacteria; therefore, their skin secretes antimicrobial peptides to protect them from infection.
cDNAs encoding precursors of 728 antimicrobial peptides, including all the precursors of the confirmed 80 native peptides, were cloned from the constructed antimicrobial peptides cDNA libraries of nine Chinese odorous frogs. These 728 antimicrobial peptides were grouped into 97 different families in which 71 novel families were identified. Out of these 728 antimicrobial peptides, 662 antimicrobial peptides were novel and 28 antimicrobial peptides were reported previously in other frog species.
It was concluded that identical antimicrobial peptides were widely distributed in odorous frogs and 49 presently identified antimicrobial peptides could find their identical molecules in different amphibian species. While purified peptides showed strong antimicrobial activities against 4 tested microbe strains, 23 deduced peptides were synthesized and their bioactivities, including antimicrobial, antioxidant, hemolytic, immunomodulatory and insulin-releasing activities, were evaluated.
The researchers hope their work will lead to the development of peptide antibiotics. Perhaps their work can also be adapted for the development of new antimicrobials for cosmetics and other consumer products. The study was funded by the National Basic Research Program of China and The National Natural Science Foundation of China.