Nicotinic Cholinergic Receptors in Rat Brain.

摘要

We have examined the molecular bond requirements of 3Hacetylcholine 3HACh nicotinic binding sites in rat brain. Reduction of disulfide bonds in vitro with the reducing agent dithiothreitol (DTT) resulted in a decrease in the number of 3HACh binding sites that could be measured, but the affinity of the remaining sites was unaltered. The effect of DTT was concentration-dependent, and it was reversed by reoxidation of the reduced disulfide bonds, with 5,5-dithiobis-2-nitrobenzoic acid. The reversibility of the DTT effect was prevented by p-chloromercuribenzoic acid, which forms thiol complexes with exposed sulfhydryl groups. The data indicate that disulfide bonds at or near the 3HACh recognition site are critical for binding of acetylcholine.