Studies on Peptides. CXXXVI. : Solution-Phase Synthesis of a 37-Residue Peptide Amide Corresponding to the Entire Amino Acid Sequence of Human Calcitonin Gene-Related Peptide (hCGRP)

Abstract

The heptatriacontapeptide amide corresponding to the entire amino acid sequence of human calcitonin gene-related peptide (hCGRP) was synthesized by assembling seven peptide fragments in solution, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid and subsequent air-oxidation to establish the disulfide bridge. The S-1-adamantyl group of the Cys residue was removed in two ways; one was by treatment with the above acid, together with the other protecting groups employed, and the other was selectively by treatment with(CF₃COO)₃Tl. The synthetic peptide produced a significant increase of cyclic adenosine monophosphate in calvaria and brain of a newborn rat, but suppressed ⁴⁵Ca-release from mouse calvaria stimulated by parathyroid hormone.