Studies on Peptides. CVI. Synthesis of a Physalaemin-like Peptide, [Lys⁵, Thr⁶]-Physalaemin, isolated from the Skin of a Frog, Uperoleia rugosa

Abstract

An undecapeptide amide, H-Pyr-Ala-Asp-Pro-Lys-Thr-Phe-Tyr-Gly-Leu-Met-NH₂, corresponding to the entire amino acid sequence of an amphibian peptide, [Lys⁵, Thr⁶]-physalaemin, was synthesized using the thioanisole-mediated trifluoromethanesulfonic acid deprotection procedure. The synthetic peptide was as active as the natural peptide, in terms of the contractility in guinea pig ileum, and its potency relative to that of synthetic substance P was 0.467.