Molecular Determinants of the Intrinsic Efficacy of the Antipsychotic Aripiprazole

Abstract

Partial agonists of the dopamine D2 receptor (D2R) have been developed to treat the symptoms of schizophrenia without causing the side effects elicited by antagonists. The receptor-ligand interactions that determine the intrinsic efficacy of such drugs, however, are poorly understood. Aripiprazole has an extended structure comprising a phenylpiperazine primary pharmacophore and a 1,2,3,4-tetrahydroquinolin-2-one secondary pharmacophore. We combined site-directed mutagenesis, analytical pharmacology, ligand fragments, and molecular dynamics simulations to identify the D2R-aripiprazole interactions that contribute to affinity and efficacy. We reveal that an interaction between the secondary ph..