Specific binding of ATP to extracellular sites on Torpedo acetylcholine receptor.
The beta- and delta-subunits of the nicotinic acetylcholine receptor from Torpedo californica were covalently photolabeled at the synaptic surface with the ATP photoaffinity analogue [alpha-32P]-8-azido-ATP. The specificity of labeling for nucleotide binding sites was demonstrated by the saturation of labeling with increasing concentration of 8-azido-ATP and the inhibition of photolabeling by ATP. Protection studies suggest that the binding sites for the photolabel are unique and are not associated with the cholinergic ligand binding sites.
Department of Biochemistry, University of Minnesota, St. Paul 55108.
B J
BJ
Carlson
M A
MA
Raftery
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D001386:Azides / Q000378:metabolism; D001665:Binding Sites; D010777:Photochemistry; D011978:Receptors, Nicotinic / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013569:Synapses / Q000378:metabolism; D014101:Torpedo
D000345:Affinity Labels; D001386:Azides; D011978:Receptors, Nicotinic; C022571:adenosine 5'-O-(3-thiotriphosphate); C017040:8-azidoadenosine 5'-triphosphate; D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase