THE CORRECTED PRIMARY STRUCTURE OF CHICKEN (AVIAN) PANCREATIC-POLYPEPTIDE

Chicken (avian) pancreatic polypeptide was the first member of the pan creatic polypeptide (PP)/neuropeptide Y (NPY) superfamily to be discov ered and structurally-characterised. In this 36 amino acid residue, C- terminally amidated peptide, residues 22 and 23 were identified as Asp and Asn, respectively. However, sequencing of chicken PP using modem automated gas-phase sequencing technology has revealed that the origin al primary structure is incorrect in that residue 22 is Asn and that r esidue 23 is Asp. After digestion of chicken PP with endoproteinase As p-N, fragments of chicken PP corresponding in molecular mass to residu es 16-22 and 23-36, were unequivocally identified. The corrected prima ry structure of chicken PP is therefore: n-Gln-Tyr-Leu-Asn-Val-Val-Thr -Arg-His-Arg-Tyr-NH2.