DIVINYL ETHER SYNTHASE FROM GARLIC (ALLIUM-SATIVUM L) BULBS - SUBCELLULAR-LOCALIZATION AND SUBSTRATE REGIOSPECIFICITY AND STEREOSPECIFICITY

Sub-cellular localization and some properties of 13-hydroperoxide-spec ific divinyl ether synthase from garlic bulbs were studied, Sub-cellul ar fractions from garlic bulbs were incubated with 4](9Z,11E,13S)-13-h ydroperoxy-9,11-octadecadienoic acid (13-HPOD). The predominant part o f divinyl ether synthase activity from garlic bulbs was found in the m icrosomal fraction. The enzyme utilizes 13(S)-HPOD as its preferential substrate, Other hydroperoxides, including 9(S)-HPOD, gave much poore r yields of divinyl ethers, Unreacted hydroperoxide after incubation o f 13(R,S)-HPOD with enzyme was composed of up to 94% 13(R)-HPOD, Thus, divinyl ether synthase possesses stereoselectivity, utilizing prefere ntially the (S)-enantiomer.