Ornithokinin (avian bradykinin) from the skin of the Chinese bamboo odorous frog, Odorrana versabilis.

Abstract

One of the most widespread and abundant families of pharmacologically active peptides in amphibian defensive skin secretions is the bradykinins and related peptides. Despite retaining certain primary structural attributes that assign them to this peptide family, bradykinins and related peptides are unique among amphibian skin peptides in that they exhibit a wide range of primary structural variations, post-translational modifications and/or N-terminal or C-terminal extensions. Initially it was believed that their high degree of primary structural heterogeneity was reflective of random gene mutations within species, but latterly, there is an increasing body of evidence that the spectrum of structural modifications found within this peptide family is reflective of the vertebrate predator spectrum of individual species. Here we report the discovery of ornithokinin (avian bradykinin - Thr(6) , Leu(8) -bradykinin) in the skin secretion of the Chinese bamboo odorous frog, Odorrana versabilis. Molecular cloning of its biosynthetic precursor-encoding cDNA from a skin secretion-derived cDNA library revealed a deduced open-reading frame of 86 amino acid residues, encoding a single copy of ornithokinin towards its C-terminus. The domain architecture of this ornithokinin precursor protein was consistent with that of a typical amphibian skin peptide and quite different to that of the ornithokininogen from chicken plasma. Ornithokinin was reported to induce hypotension in the chicken and to contract the chicken oviduct but to have no obvious effect on the rat uterus. However, in this study, synthetic ornithokinin was found to contract the rat ileum (EC50  = 539 nM) and to increase contraction frequency in the rat uterus (EC50  = 1.87 μM).

• Authors: Peng Lyu, Lilin Ge, Lei Wang, Xiaoxiao Guo, Huiling Zhang, Yihan Li, Yu Zhou, Mei Zhou, Tianbao Chen, Chris Shaw
• Journal: Journal of peptide science : an official publication of the European Peptide Society (J Pept Sci) Vol. 20 Issue 8 Pg. 618-24 (Aug 2014) ISSN: 1099-1387 [Electronic] England
• PMID: 24771465 (Publication Type: Journal Article)
• Copyright: Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

Chemical References

• ornitho-kinin
• Bradykinin

Topics

• Amino Acid Sequence
• Animals
• Base Sequence
• Bradykinin (analogs & derivatives, chemistry, pharmacology)
• Chickens
• Female
• Molecular Sequence Data
• Muscle Contraction (drug effects)
• Oviducts (drug effects)
• Ranidae
• Rats
• Skin (chemistry)
• Uterine Contraction (drug effects)