PT  - JOURNAL ARTICLE
AU  - A K Naidu
AU  - A K Naidu
AU  - A P Kulkarni
TI  - Aldrin epoxidation. Catalytic potential of lipoxygenase coupled with linoleic acid oxidation.
DP  - 1991 Jul 01
TA  - Drug Metabolism and Disposition
PG  - 758--763
VI  - 19
IP  - 4
4099  - http://dmd.aspetjournals.org/content/19/4/758.short
4100  - http://dmd.aspetjournals.org/content/19/4/758.full
SO  - Drug Metab Dispos1991 Jul 01; 19
AB  - Epoxidation of aldrin was studied using highly purified soybean lipoxygenase in the presence of linoleic acid. Dieldrin, the primary stable reaction product, was quantified by electron-capture gas chromatography. The oxidation of aldrin to dieldrin was dependent on the concentration of linoleic acid, aldrin, and enzyme. The epoxidation was linear with time and exhibited a pH optimum of 7.4. The optimal conditions to observe maximum enzyme velocity included the presence of 0.25 mM linoleic acid, 200 microM aldrin, and 20 nM enzyme. Lipoxygenase inhibitors nordihydroguaiaretic acid, phenidone, 5,8,11-eicosatriynoic acid, and 5,8,11,14-eicosatetraynoic acid significantly inhibited epoxidation in a dose-dependent manner. Catalytic potential of lipoxygenase as expressed in terms of its turnover numbers was approximately 4.0 nmol/min/nmol of enzyme, and it appears that lipoxygenase is up to 20 times a better catalyst of aldrin epoxidation than cytochrome P-450. These results suggest that lipoxygenase, which is widely distributed in plants and animals, may represent yet another important pathway for epoxidation of aldrin.