Xenobiotic oxidation by hydroperoxidase activity of lipoxygenase immobilized by adsorption on controlled pore glass

This work describes the immobilization of lipoxygenase by adsorption on controlled pore glass and the study of the use of the hydroperoxidase activity of lipoxygenase for the oxidative detoxification of xenobiotics. The efficiency of the coupling has been checked by determination of dioxygenase activity using linoleic acid as substrate. The enzyme was coupled more efficiently at pH 9.0. After coupling the stability of the systems is maintained in a broad pH range. Immobilized lipoxygenase produces the oxidation of chlorpromazine at pH 3.5 in the presence of hydrogen peroxide with a catalytic efficiency (2.84 min−1 mM−1) near to the obtained with free enzyme in the same experimental conditions. The stability of this system allows its use in a biorreactor for continuous reaction. The possibility of the application of this system for N-demethylation reaction has been checked using the pesticide aminocarb as substrate. The results obtained shows that immobilized lipoxygenase produces the N-demethylation of aminocarb in the presence of hydrogen peroxide at pH 6.3. The efficiency of the reaction (36 min−1 mM−1) it is clearly higher than the obtained when free enzyme was assayed in the same experimental conditions (10.55 min−1 mM−1). In addition, the high stability of the system makes feasible its utilization in a biorreactor for continuous treatment of samples.