Inactivation of the opiate receptor in bovine caudate nucleus by azide enkephalin analogs.
Photoaffinity labels have been prepared to react with the opiate receptor. The compounds are based on analogs of the enkephalins but involve significant changes in structure which allow introduction of azido substituents while still retaining binding affinity. The compounds designed have been shown to have biological activity in guinea pig ileum tests. A good correlation is obtained between the Kd  for stereospecific binding and the Kd for activity in the guinea pig test. Affinity to and inactivation of the opiate receptor is obtained with two of the compounds which have affinities and activities comparable to morphine.
D000345:Affinity Labels; D000818:Animals; D001386:Azides / Q000138:chemical synthesis / Q000494:pharmacology*; D001667:Binding, Competitive; D001681:Biological Assay; D002417:Cattle; D002421:Caudate Nucleus / Q000378:metabolism*; D004558:Electric Stimulation; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000138:chemical synthesis / Q000494:pharmacology*; D005048:Etorphine / Q000378:metabolism; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D007700:Kinetics; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D013329:Structure-Activity Relationship
D000345:Affinity Labels; D001386:Azides; D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid; D005048:Etorphine