Proenkephalin
Proenkephalin, formerly known as proenkephalin A, is an endogenous opioid polypeptide hormone which, via proteolyic cleavage, produces the enkephalin peptides Met-enkephalin|enkephalin, and to a lesser extent, Leu-enkephalin|enkephalin. Upon cleavage, each proenkephalin peptide results in the generation of four copies of enkephalin, two extended copies of enkephalin, and one copy of enkephalin. Contrarily, enkephalin] is predominantly synthesized from prodynorphin, which produces three copies of it per cleavage, and no copies of enkephalin. Other endogenous opioid peptides produced by proenkephalin include adrenorphin, amidorphin, BAM-18, BAM-20P, BAM-22P, peptide B, peptide E, and peptide F.
