Studies of nicotinic acetylcholine receptor protein from rat brain |
| |
Authors: | William McChesney Moore Robert N Brady |
| |
Institution: | Department of Biochemistry, Vanderbilt University, Nashville, Tenn. 37232 U.S.A. |
| |
Abstract: | Specific binding of 125I-labeled α-bungarotoxin to a 34 800 × g pellet of a whole rat brain homogenate has been obtained at levels 2 pmol toxin per g of whole brain with a Kd of 8·10?9 M. Binding is reduced 90% by 10?5 M (+)- tubocurarine chloride and 10?4 M nicotine, whereas concentrations of 10?4 M choline chloride, atropine sulfate and eserine sulfate have essentially no effect on toxin binding. These results compare closely with those obtained from binding studies with 125I-labeled α-bungarotoxin and soluble acetylcholine receptor protein preparations form Torpedo nobiliana; suggesting that this mammalian receptor protein is nicotinic in character.Extraction of the 34 800 × g pellet with 1% Emulphogene yields a soluble fraction with specifically binds 125I-labeled α-bungarotoxin with a Kd of 5·10?9 M. Nicotine and α-bungarotoxin at concentrations of 10?5 M abolish toxin- receptor complex formation and carbachol and (+)-tubocurarine chloride reduce complex formation 35–40% at similar concentrations. Eserine sulfate, atropine sulfate, decamethonium, and pilocarpine had no effect on complex formation at concentrations of 10?5 M. |
| |
Keywords: | To whom correspondence should be addressed |
本文献已被 ScienceDirect 等数据库收录! |
|