title: Allosteric modulation by leucine-enkephalin of [3H]naloxone binding in rat brain.
abstract: The interaction of morphine and leucine-enkephalin with the binding site labeled by [3H]naloxone in the presence of sodium was compared. The effect of fixed concentrations of morphine and leucine enkephalin on the saturation binding of [3H]naloxone demonstrated that whereas morphine was a competitive inhibitor, leucine enkephalin caused a dose-dependent masking of binding sites. From these data we conclude that the enkephalin receptor is allosterically coupled to the morphine receptor.
mesh_terms: D000495:Allosteric Site / Q000187:drug effects; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004743:Enkephalin, Leucine; D004745:Enkephalins / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009270:Naloxone / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000378:metabolism*
chemical_list: D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid; D009270:Naloxone; D004743:Enkephalin, Leucine