Peptide YY (PYY) is a 36-amino-acid peptide studied in laboratory research as a member of the neuropeptide Y family of peptides, alongside NPY and pancreatic polypeptide. It is used in vitro as a tool compound for the Y receptor family (Y1, Y2, Y4, Y5), a group of class A G protein-coupled receptors, in receptor pharmacology and cell culture studies.

Structure: PYY has the sequence 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, with an amidated C-terminus and the family-characteristic PP-fold tertiary motif. Laboratory studies distinguish full-length PYY 1-36 from the truncated PYY 3-36 form produced by dipeptidyl peptidase-IV cleavage, because the two forms show different Y receptor selectivity profiles in vitro — a standard example of how a single processing step changes a peptide’s laboratory behavior. Identity and purity are confirmed by HPLC and mass spectrometry, and the lot-matched COA is reviewed before use.

Laboratory applications: receptor-binding and cell culture assays comparing PYY 1-36 and PYY 3-36 across Y receptor subtypes, structure-activity studies of the PP-fold family, DPP-IV processing studies in defined in vitro systems, and use as a reference agonist alongside selective antagonist controls. Vehicle controls, analytical verification, and replication are standard. In vitro findings describe receptor behavior in laboratory systems only; no conclusions about human use can be drawn from them.

Analytical notes: store lyophilized material sealed, protected from light and moisture; verify identity and purity by HPLC/MS on receipt; confirm which molecular form (1-36 or 3-36) a lot contains before designing an experiment; avoid repeated freeze-thaw cycles; record lot numbers in laboratory documentation.

Disclaimer: This material is supplied for laboratory research purposes only. Not for human consumption. Not for medical, therapeutic, diagnostic, or veterinary use. No dosing, reconstitution-for-use, or efficacy information is provided or implied.

Citations: Tatemoto K, isolation and characterization of peptide YY (1982); Batterham RL et al., PYY 3-36 laboratory studies, Nature (2002); standard HPLC/MS peptide characterization methods.