Isolation and primary structure of human peptide YY.

The isolation, primary structure and chemical synthesis of human peptide YY (PYY) are described. The peptide was purified from human colonic extracts using a chemical method which detected the C-terminal tyrosine amide structure of PYY. Human PYY consists of 36 amino acid residues and the complete amino acid sequence is: Tyr-Pro-Ile-Lys-Pro-Glu-Ala-Pro-Gly-Glu- Asp-Ala-Ser-Pro-Glu-Glu-Leu-Asn-Arg-Tyr-Tyr-Ala-Ser-Leu-Arg-His-Tyr-Leu- Asn-Leu-Val-Thr-Arg-Gln-Arg-Tyr-NH2. The differences between the structures of porcine and human PYY are at positions 3 (Ala/Ile replacement) and 18 (Ser/Asn). Synthetic human PYY prepared using a solid-phase synthetic technique was found to be structurally identical to the natural peptide.