An antibody to a peptide specified by an RNA that is complementary to gamma-endorphin mRNA recognizes an opiate receptor.

The putative delta-opiate receptor complex has been identified by a new approach which employed an antibody that is directed against a peptide which binds gamma-endorphin and is specified by RNA that is complementary to that of gamma-endorphin mRNA. This antibody competes with beta-endorphin and naloxone for binding sites on the surface of neuroblastoma X glioma NG108-15 hybrid cells. The opiate receptor complex has an apparent molecular weight of 210,000 and is composed of four noncovalently associated subunits with apparent molecular weights of 68,000, 58,000, 45,000 and 30,000.