Computer analysis of the effect of beta-endorphin and dynorphin and related compounds on opioid binding to mouse brain membrane

Abstract

The binding of three tritiated opioid agonists—dihydromorphine, d-ala 2- d-leu 5-enkephalin and ethylketocyclazocine—was subjected to competition by unlabeled beta-endorphin, dynorphin-(1–13), and various fragments of these peptides, and the results analyzed by a computer program that we developed in an earlier study [11]. Peptides in both groups bound with highest affinity to sites 1 and 3 in our 4-site model, corresponding to the mu and delta sites of conventional classifications, with the dynorphin peptides also interacting with site 2, the kappa site. These results are discussed in relationship to the possible biological roles of these peptides as analgesics or as modulators of analgesia.