Divinyl ether synthase from garlic ( Allium sativum L.) bulbs: sub-cellular localization and substrate regio- and stereospecificity

Abstract

Sub-cellular localization and some properties of 13-hydroperoxide-specific divinyl ether synthase from garlic bulbs were studied. Sub-cellular fractions from garlic bulbs were incubated with [1− 14C](9 Z,11 E,13 S)-13-hydroperoxy-9,11-octa-decadienoic acid (13-HPOD). The predominant part of divinyl ether synthase activity from garlic bulbs was found in the microsomal fraction. The enzyme utilizes 13( S)-HPOD as its preferential substrate. Other hydroperoxides, including 9( S)-HPOD, gave much poorer yields of divinyl ethers. Unreacted hydroperoxide after incubation of 13( R, S)-HPOD with enzyme was composed of up to 94% 13( R)-HPOD. Thus, divinyl ether synthase possesses stereoselectivity, utilizing preferentially the ( S)-enantiomer.