Different molecular weight forms of opioid receptors revealed by polyclonal antibodies.
Polyclonal antibodies were raised against a purified opioid receptor from bovine brain (Cho, et. al., 1986), and shown to inhibit 3H-diprenorphine binding to this receptor in a dose-dependent fashion. These antibodies were then used to characterize opioid-binding material present in rat brain and in NG108-15 neuroblastoma-glioma hybrid cells. Western blot analysis revealed that the antibodies reacted with a single species of 58,000 molecular weight in rat brain membranes; this closely corresponds in size to the bovine opioid receptor used to raise the antibodies. In contrast, the polyclonal antibodies reacted with a 45,000 molecular weight species in NG108-15 neuroblastoma-glioma hybrid cells; moreover, this band was specifically reduced in NG108-15 cells in which opioid receptors had been down-regulated by incubation with D-ala2-D-leu5-enkephalin for 24 hours. Thus at least two distinct opioid receptor molecules have been identified, which have antigenic similarities.
Roy
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Department of Pharmacology, University of California, San Francisco 94143.
Zhu
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Lee
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Loh
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D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D001923:Brain Chemistry; D002417:Cattle; D002462:Cell Membrane / Q000032:analysis; D004174:Diprenorphine / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005910:Glioma / Q000032:analysis; D006822:Hybrid Cells / Q000032:analysis; D007114:Immunization; D007163:Immunosorbent Techniques; D009447:Neuroblastoma / Q000032:analysis; D011817:Rabbits / Q000276:immunology; D051381:Rats; D011957:Receptors, Opioid / Q000032:analysis* / Q000276:immunology / Q000378:metabolism
D000906:Antibodies; D011957:Receptors, Opioid; D004174:Diprenorphine