In a conventional manner, the tritriacontapeptide amide corresponding to the entire amino acid sequence of the desulfated form of porcine cholecystokinin-pancreozymin (CCKPZ) was synthesized by applying protecting groups removable by hydrogen fluoride. Synthetic peptide, though it is not too biological active, was smoothly and efficiently converted to the labeled compound with 126I (specific activity 200-250 μci/μg).
