Solubilization and partial characterization of adenosine binding sites from rat brainstem

Abstract

Binding sites for adenosine were solubilized from rat brainstem membranes with either sodium cholate, sodium deoxycholate or 3-[3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate. About 30% of the binding activity were released by these detergents as assayed by [3H]phenylisopropyladenosine (PIA) binding. Specific [3H]PIA binding to the solubilized fraction was saturable and was found to be a monophasic saturation profile. In contrast, [3H]PIA binding sites. By gel filtration on a Sepharose CL-6B biphasic profile suggesting the presence of two binding sites. By gel filtration on a Sepharose CL-6B column, the adenosine binding site—detergent complex was estimated to have app. Mr 280 000 and rs = 5.4 nm