Abstract
Aniline hydroxylation with a hemin-cysteine system was studied under various conditions as a model for cytochrome P-450 enzymes. The reaction was characterized by using various inhibitors, such as hydroxyl radical scavengers, a singlet oxygen trapping agent, superoxide dismutase and catalase. The system was compared with simple model systems consisting of cupric ion, ascorbic acid and hydrogen peroxide or the Udenfriend system. The hemin-cysteine model system was not inhibited appreciably by any of the inhibitors tested. On the basis of these findings and the fact that the thiolate-heme iron linkage was found to be present in the hemin-cysteine system, a possible mechanism for hydroxylation by the model system is proposed.
