ALLOSTERIC COUPLING BETWEEN MORPHINE AND ENKEPHALIN RECEPTORS INVITRO
- 1 January 1982
- journal article
- research article
- Vol. 21 (3) , 548-557
Abstract
[3H]Leu enkephalin apparently labels a single class of binding sites (the enkephalin receptor) and morphine may allosterically induce a masking of enkephalin receptors as a consequence of binding to a receptor (the morphine receptor) not labeled by the 3H-peptide. [3H]Etorphine can evidently be used to label selectively the morphine receptor and the Ki of morphine, etorphine and human .beta.-endorphin for the [3H]etorphine binding site closely approximate the concentration of these drugs which produce a 1/2-maximal decrease in the number of enkephalin receptors. An examination of the interaction of leucine enkephalin and met enkephalin with the morphine receptor has demonstrated that the pentapeptides are not competitive inhibitors of [3H] etorphine binding and that they have much lower affinities for the morphine receptor than previously thought. Distinct morphine and enkephalin receptors may coexist in an opioid-receptor complex.This publication has 6 references indexed in Scilit:
- Dynorphin-(1-13), an extraordinarily potent opioid peptide.Proceedings of the National Academy of Sciences, 1979
- Specific protection of the binding sites of D-Ala 2 -D-Leu 5 - enkephalin (δ-receptors) and dihydromorphine (μ-receptors)Proceedings of the Royal Society of London. B. Biological Sciences, 1979
- Multiple opiate receptors. Enkephalins and morphine bind to receptors of different specificity.Journal of Biological Chemistry, 1979
- Opiate receptor binding affected differentially by opiates and opioid peptidesEuropean Journal of Pharmacology, 1979
- METABOLIC DISPOSITION OF RADIOLABELED ENKEPHALINS INVITRO AND INSITU1978
- Endogenous opioid peptides: multiple agonists and receptorsNature, 1977