A bombesin-like peptide from skin of Sanguirana varians.

Bombesin-like peptides (BLPs) are a family of neuro-endocrinic peptides that mediates a variety of biological activities. A BLP named bombesin-SV from the skin secretions of the frog, Sanguirana varians, was purified and characterized. Its amino acid sequence is pEMIFGAPMWALGHLM-NH2 determined by Edman degradation and mass spectrometry. The cDNA encoding bombesin-SV precursor was cloned from skin cDNA library of S. varians. The precursor is composed of 67 amino acid residues including a copy of mature bombesin-SV. Two predicted enzymatic processing sites (-Lys-Arg-) are flanked at the mature bombesin-SV sequence. In the in vitro myotropic contraction experiment, the synthesized bombesin-SV displayed the stimulating effect toward rat stomach strips, suggesting that bombesin-SV acts as agonist as most other BLPs do.