The mechanism of the irreversible inhibition of rat liver monoamine oxidase by iproniazid (Marsilid)

Abstract

Inhibition of rat-liver monoamine oxidase by iproniazid is first-order and irreversible and has a high energy of activation. Since the inhibition reaction requires O2 it is postulated that irreversible inhibition is the result of dehydrogenation of iproniazid at the active center of the enzyme. In the presence of KCN inhibition of mitochondrial monoamine oxidase is much increased. This effect is augmented by prior shaking of the mitochondria in O2 with KCN.