Isolation and structure of dynorphin, an opioid peptide, from porcine duodenum

The presence of endogenous ligands of opiate receptors in gastrointestinal organs has been demonstrated by both bioassay and immunoassay but so far no ligand has been precisely identified. We report here the purification from porcine duodenum of an opioid peptide whose structure coincides with that of the pituitary opioid, dynorphin1. Only the N-terminal… (More)