Inactivation of benzodiazepine binding sites by N-ethylmaleimide

The benzodiazepine receptors of bovine brain membranes have been identified by the specific binding of radiolabeled [3H]diazepam. Pretreatment of membranes with N-ethylmaleimide causes a dose- and time-dependent decrease of 45 to 60% in the number of binding sites. No decrease occurs when membranes are pretreated with N-ethylmaleimide before administration, or in the presence, of diazepam. Binding of [3H]diazepam to the remaining sites occurs with the same characteristics as binding to the untreated receptor population.