title: Photoaffinity inactivation of the enkephalin receptor.
abstract: An arylazide enkephalin derivative, [D-Ala2,Met5]enkephalin-Tyr-N-(2-nitro-4-azidophenyl) ethylenediamine (ETN), has been synthesized. In the dark, it inhibited the binding of [3H]enkephalinamide to enkephalin receptor-rich NG-108 cell membranes with an I50 = 2.2 X 10(-8) M or KI = 7 X 10(-9) M, assuming competitive inhibition. Photolysis of membranes in the presence of ETN caused irreversible inactivation of the enkephalin receptor, but inactivation was prevented by the addition of enkephalin, the half-effective concentration being 3 x 10(-9) M. ETN appears to be an effective photoaffinity label for the enkephalin receptor.
mesh_terms: D000345:Affinity Labels / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D005910:Glioma; D006822:Hybrid Cells; D007700:Kinetics; D051379:Mice; D009447:Neuroblastoma; D010782:Photolysis; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000345:Affinity Labels; D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid