Reconstitution of the muscarinic acetylcholine receptor. Guanine nucleotide-sensitive high affinity binding of agonists to purified muscarinic receptors reconstituted with GTP-binding proteins (Gi and Go).

摘要: Muscarinic acetylcholine receptors purified from porcine brain were reconstituted with two kinds of GTP-binding proteins (Gi and Go). The binding agonists was affected by guanine nucleotides when the receptor either Gi or Go, but not in absence one proteins. displacement curves for [3H]quinuclidinyl benzylate [( 3H]QNB) explained assuming there are sites different affinities a given agonist. proportion high affinity site increased increasing concentrations proteins, maximum value represented 50-70% total [3H]QNB-binding sites. Reconstitution both Go did increase any further. These results indicate that interact same site, which rules out possibility muscarinic receptors, interacting other Go. GDP as well GTP decreased conversion to during incubation less than 1%, indicating effect is due its GTP, suppresses their interaction receptor.