Purification and characterization of a benzene hydroxylase from rat liver mitochondria.

An enzyme has been purified to electrophoretic homogeneity from rat liver mitoplasts which metabolizes benzene to phenol. The enzyme has a Mr of 52,000 and requires NADPH, adrendoxin, and adrenodoxin reductase for activity. Benzene hydroxylase activity could be inhibited by carbon monoxide and SKF-525A, and by specific inhibitors of microsomal benzene metabolism. The purified enzyme also oxidized phenol to catechol. The data suggest that a cytochrome P-450 of mitochondrial origin is involved in benzene metabolism, and provide another example of a role for the mitochondrion in xenobiotic activation.