ENZYMATIC CONVERSION OF ALDRIN TO DIELDRIN WITH SUBCELLULAR COMPONENTS OF PEA PLANTS

Subcellular fractions from peas were obtained by differential centrifugation after the plants had been grown under both sterile and nonsterile conditions. Enzymatic conversion of aldrin to dieldrin was achieved with different cell fractions. Of the total dieldrin recovered from all cell fractions, 11% was produced by the “nuclei”-pellet (1000 G), 18% by the “mitochondria”-pellet (10,000 G), 17% by the ;“microsome”-pellet and 54% by the soluble fraction (105,000 G). The enzymatic activity was increased with Cu2- and Fe2+ by 123 and 56%, and was inhibited by Mn2-, sesamex, and SKF 525-A by 30, 72, and 80%, respectively. The effects of Cu2+ and Fe2+ could be nullified by the addition of EDTA to the reaction mixtures. The enzyme(s) in peas appeared different from that described in animal tissues, since: It is specific for aldrin and did not epoxidize the endo-endo isomer of aldrin (isodrin) or heptachlor; cofactors, such as NAD, NADP, and NADPH did not affect the rate of epoxidation of aldrin; and most of the enzymatic activity was found in the soluble fraction and not in the “microsome”-pellet. © 1969, American Chemical Society. All rights reserved.