Inactivation of aldehyde dehydrogenase in intact rat liver mitochondria by dopamine

Aldehyde dehydrogenase (EC 1.2.1.3) within isolated rat liver mitochondria was inactivated by incubation with dopamine. Concurrent with this inactivation, incorporation of radioactivity from 14C-labelled dopamine into three mitochondrial matrix proteins (subunit mol.wt. = 120,000; 54,000; 20,000 daltons) occurred. The 54,000 mol.wt. protein also interacted with antihuman mitochondrial aldehyde dehydrogenase antibody. Inactivation of aldehyde dehydrogenase by dopamine occurred more readily in females than in males. Use of monoamine oxidase (EC 1.4.3.4) inhibitors (deprenyl and clorgyline) partially protected against inactivation. Monoamine oxidase catalyzed conversion of to 3,4-dihydroxyphenylacetaldehyde only partially accounted for aldehyde dehydrogenase activity loss.