Inactivation of [(35)S]t-butylbicyclophosphorothionate binding sites by the arginine reagent, 2,3-butanedione.
The "cage" convulsant [(35)S]t-butylbicyclophosphorothionate ([(35)S]TBPS) binds with high affinity to specific sites "at" or "near" a ?-amino-butyric acid (GABA)-gated chloride channel according to current hypothesis. We now report that pretreatment of membranes with 2,3-butanedione, an arginine-specific reagent, causes a dose- and time-dependent decrease in the number of [(35)S]TBPS binding sites. No decrease occurs when membranes are pretreated with 2,3-butanedione in the presence of picrotoxinin. Binding of [(35)S]TBPS to the remaining sites occurs with the same characteristics as binding to the untreated receptor population.
Martini
C
C
Istituto Policattedra di Discipline Biologiche, Università di Pisa, Via Bonanno, 56100 Pisa, Italia; Istituto di Chimica Biologica, Università di Parma, 43100 Parma, Italia.
Pacini
R
R
Lucacchini
A
A