Binding of alpha-bungarotoxin and cholinergic ligands to acetylcholine receptors in the membrane of skeletal muscle.
A membrane fraction enriched in acetylcholine receptors was prepared from denervated cat leg muscles. 97% of the alpha-bungarotoxin-binding sites in the dispersed membranes are sensitive to nicotinic cholinergic ligands. In intact msucle, 90% are. A filtration assay of the binding to the membranes of tritiated alpha-bungarotoxin, as retarded by these ligands, provides a convenient system for the determination of affinities of ligands for the muscle receptor in its membrane-bound state. Affinities were found thus for 6 nicotinic ligands. An allosteric system, rather than desensitisation, may explain the high affinities observed for certain ligands.
D000109:Acetylcholine / Q000378:metabolism; D000495:Allosteric Site; D000818:Animals; D001285:Atropine / Q000378:metabolism; D002038:Bungarotoxins / Q000378:metabolism*; D002217:Carbachol / Q000378:metabolism; D002415:Cats; D003650:Decamethonium Compounds / Q000378:metabolism; D005703:Gallamine Triethiodide / Q000378:metabolism; D006584:Hexamethonium Compounds / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism*; D012508:Sarcolemma / Q000378:metabolism*; D014403:Tubocurarine / Q000378:metabolism
D002038:Bungarotoxins; D003650:Decamethonium Compounds; D006584:Hexamethonium Compounds; D011950:Receptors, Cholinergic; D001285:Atropine; D002217:Carbachol; D000109:Acetylcholine; D005703:Gallamine Triethiodide; D014403:Tubocurarine