Regulation of the solubilized bovine cerebral cortex muscarinic receptor by GTP and Na+.
The muscarinic acetylcholine receptor was solubilized, in a sensitive form for GTP and Na+, from bovine cerebral cortex using a zwitterionic detergent 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate. The solubilized muscarinic receptor displayed characteristics as follows: (1) high affinity to nanomolar concentration of Z-[3H]quinuclidinyl benzilate; (2) muscarinic agonists and antagonists had similar inhibitory potencies as on the membrane-bound receptor; (3) without Na+, GTP did not significantly alter the binding affinity of muscarinic agonists and antagonists; (4) GTP in the presence of Na+, selectively decreased the affinity of muscarinic agonists, carbamylcholine and oxotremoline, but not the antagonist binding affinity; (5) Na+ in the absence or presence of GTP, reduced both muscarinic agonist and antagonist affinities.
D000818:Animals; D002417:Cattle; D002540:Cerebral Cortex / Q000378:metabolism*; D003902:Detergents; D006160:Guanosine Triphosphate / Q000494:pharmacology*; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000302:isolation & purification*; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000302:isolation & purification*; D012964:Sodium / Q000494:pharmacology*; D012995:Solubility
D003902:Detergents; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D006160:Guanosine Triphosphate; D012964:Sodium