Oligopeptides as neuropeptide Y Y4 receptor ligands: identification of a high-affinity tetrapeptide agonist and a hexapeptide antagonist.

Within the family of neuropeptide Y (NPY) receptors, the Y4 receptor (Y4R) is unique as it prefers pancreatic polypeptide (PP) over NPY and peptide YY (PYY). Today, low molecular weight Y4R ligands...