POSITIONAL SPECIFICITY OF KETODIENES FROM LINOLEIC-ACID AEROBICALLY FORMED BY LIPOXYGENASE ISOZYMES FROM KIDNEY BEAN AND PEA

Two lipoxygenase isozymes (LOX-1 and LOX-2) from kidney bean and pea f lours were purified by a combination of ammonium sulfate fractionation , gel filtration, and ion-exchange chromatography. Besides the product ion of hydroperoxides, LOX-1 catalyzed the aerobic formation of ketodi enes. The positional and geometrical isomers were separated and quanti fied by HPLC. LOX-1 yielded approximately equal proportions of 9- and 13-hydroperoxides and the 9- and 13-ketodienes; LOX-2 formed mainly th e 13-hydroperoxide isomer.