Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 94305.
Bovine pancreastatin, a 47 amino acid residue peptide, was isolated from the pancreas and the pituitary gland using a chemical method which detects its C-terminal glycine amide structure. The complete amino acid sequence of the pancreatic peptide is 74% homologous to that of porcine pancreastatin and is identical to bovine chromogranin A-(248-294), as deduced from its cDNA sequence. The sequence of the first 28 amino-terminal residues of the pituitary peptide was determined to be identical to the corresponding sequence of the pancreatic peptide. Since the pituitary peptide also contains the C-terminal glycine amide, it is therefore likely to be identical in structure to the pancreatic peptide. Thus, we conclude that bovine chromogranin A is the precursor of bovine pancreastatin. Synthetic bovine pancreastatin inhibited pancreatic exocrine secretion in a similar manner to porcine pancreastatin.