Peptide tyrosine tyrosine (PYY) was originally isolated from porcine gut, which exhibits striking sequence homology with members of the pancreatic polypeptide family, including neuropeptide tyrosine (NPY). The peptide is localized to enteroglucagon containing (L/EG) and pancreatic (A) cells in many mammalian and non-mammalian species. PYY gene expression is upregulated by various growth factors, including growth hormone and insulin-like growth factor and the physiological effects of PYY are mediated by G-protein (G alpha i2) coupled Y-type receptors (‘Y2 receptors of a PYY preferring subtype’). Various actions have been reported for PYY, including the inhibition of upper intestinal and exocrine pancreatic secretion, small intestinal water flux and as the mediator for the fat-induced ileal brake. Recently, the infusion of normal postprandial concentrations of PYY[3-36] into human volunteers has been shown to significantly decrease appetite and reduce food intake, possibly via Y2R in the arcuate nucleus. Immunohistochemical studies on mice have shown that PYY is the earliest detectable peptide in both pancreatic islets and colonic endocrine cells which suggest that PYY may be a useful marker for endocrine progenitor cells.

PYY1-36(human):
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
CAS Number: 118997-30-1; Empirical Formula (Hill Notation): C194H295N55O57; Molecular Weight: 4309.75