Docking of novel reversible monoamine oxidase-B inhibitors: efficient prediction of ligand binding sites and estimation of inhibitors thermodynamic properties

Abstract

Monoamine oxidase (MAO, EC 1.4.3.4) is a flavoenzyme bound to the mitochondrial outer membranes of the cells, which is responsible for the oxidative deamination of neurotransmitter and dietary amines. It has two distinct isozymic forms, designated MAO-A and MAO-B, each displaying different substrate and inhibitor specificities. They are the well-known target for antidepressant, Parkinson's disease and neuroprotective drugs. Elucidation of the x-ray crystallographic structure of MAO-B has opened the way for molecular modeling studies. In this research 12 reversible and MAO-B selective inhibitors have been docked computationally to the active site of the MAO-B enzyme. AutoDock 3.0.5 was employed to perform the automated molecular docking. The result of docking studies generated thermodynamic properties, such as free energy of bindings (DeltaG(b)) and inhibition constants (K (i)) for the inhibitors. Moreover, 3D pictures of inhibitor-enzyme complexes afforded valuable data regarding the binding orientation of each inhibitor in the active site of MAO-B.