Pancreatic hormones (PP) are
peptides synthesized in pancreatic
islets of Langerhans, which acts as a regulator of pancreatic and gastrointestinal functions.
The hormone is produced as a larger propeptide, which is enzymatically cleaved to yield the mature active peptide: this is 36 amino acids in length and has an amidated C terminus. The hormone has a globular structure, residues 2-8 forming a left-handed poly-proline-II-like helix, residues 9-13 a beta turn, and 14-32 an alpha-helix,held close to the first helix by hydrophobic interactions. Unlike glucagon, another peptide hormone, the structure of pancreatic peptide is preserved in aqueous solution. Both N and C termini are required for activity: receptor binding and activation functions may reside in the N and C termini respectively.