Identification and Functional Analysis of Novel Bradykinin-Related Peptides (BRPs) from Skin Secretions of Five Asian Frogs.

In recent decades, various types of bioactive substances have been identified from amphibian skin and its secretions. Bradykinin-related peptides (BRPs) are among these compounds that make up the host defence system of amphibians. In the present study, we identified six novel BRPs, amolopkinin-GN1, amolopkinin-RK1, amolopkinin-TR1, amolopkinin-LF1, ranakinin-MS1, and ranakinin-MS2, from five East Asian amphibians, Amolops granulosus, Amolops ricketti, Amolops torrentis, Amolops lifanensis, and Hylarana maosonensis. This is the first report on BRPs in the skin of these species. Physiological assays reveal that these peptides have a contractive effect on the smooth muscle of rat ileum.