Functional Analysis on GABAB Receptor Using a Reconstituted System with Purified GABAB Receptor, Gi/Go Protein and Adenylyl Cyclase

GABAb receptor was purified from the bovine cerebral cortex using baclofen-affinity gel. The eluate from the baclofen-affinity gel indicated possible presence of multiplicity in GABAb receptor. The Gi/Go protein and adenylyl cyclase prepared from the bovine cerebral cortex were reconstituted with the eluate from baclofen-affinity gel. This reconstituted system showed the GABAb receptor-mediated inhibition on the forskolin-stimulated cAMP accumulation. Subsequently, it was demonstrated that the inhibition of GABAb receptor binding by ethanol was accompanied with the decrease of GABAb receptor-mediated inhibition on forskolin-stimulated cAMP accumulation in the reconstituted systems.