Characterization Of Curaremimetic Neurotoxin Binding Sites On Cellular Membrane Fragments Derived From The Rat Pheochromocytoma Pc 12
Abstract: Studies were conducted on the properties of 125Iâ€labeled Î±â€bungarotoxin binding sites on cellular membrane fragments derived from the PC 12 rat pheochromocytoma. Two classes of specific toxin binding sites are present at approximately equal densities (50 fmol/mg of membrane protein) and are characterized by apparent dissociation constants of 3 and 60 nM. Nicotine and dâ€tubocurarine are among the most potent inhibitors of highâ€affinity toxin binding. The affinity of highâ€affinity toxin binding sites for nicotinic cholinergic agonists is reversibly or irreversibly decreased, respectively, on treatment with dithiothreitol or dithiothreitol and Nâ€ethylmaleimide. The nicotinic receptor affinity reagent bromoacetylcholine irreversibly blocks highâ€affinity toxin binding to PC 12 cell membranes that have been treated with dithiothreitol. Two polyclonal antisera raised against the nicotinic acetylcholine receptor from Electrophorus electricus inhibit highâ€affinity toxin binding. These detailed studies confirm that curaremimetic neurotoxin binding sites on the PC 12 cell line are comparable to toxin binding sites from neural tissues and to nicotinic acetylcholine receptors from the periphery. Because toxin binding sites are recognized by antiâ€nicotinic receptor antibodies, the possibility remains that they are functionally analogous to nicotinic receptors. Copyright Â© 1986, Wiley Blackwell. All rights reserved
Journal of Neurochemistry
Digital Object Identifier (DOI)
Lukas, Ronald J., "Characterization Of Curaremimetic Neurotoxin Binding Sites On Cellular Membrane Fragments Derived From The Rat Pheochromocytoma Pc 12" (1986). Neurobiology. 190.