Studies on Peptides. CXXXVII. : Conventional Solution Synthesis of Porcine Hypothalamic Growth Hormone Releasing Factor (pGRF)

A tetratetracontapeptide amide corresponding to the entire amino acid sequence of porcine hypothalamic growth hormone releasing factor (pGRF) was synthesized by a conventional solution method, by assembling nine peptide fragments followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid. The synthetic peptide was as active as synthetic human GRF-44-NH2 in an in vitro assay. A new substituted hydrazine, 2, 2, 2-trichloro-tert-butoxycarbonyl hydrazine, was employd for the preparation of a hydrazide containing Glu(OBzl). In the deprotecting step, Me2Se was empliyed to facilitate acidolytic cleavage of protecting groups, as well as reduction of Met(O).