Biosynthesis of cytidine diphosphate diglyceride by enzyme preparations from cauliflower

The activity of the enzyme responsible for the synthesis of cytidine diphosphate diglyceride has been found in the 20,000g pellet of a cauliflower (Brassica oleracea) inflorescence homogenate. Greater enzyme activity was found in the pellet after treatment with 0.02% Triton X-100, or after freezing and thawing. Activity was greater when fluoride was included in the reaction mixture. The enzyme has a pH optimum of 5.6, an optimal Mn(2+) concentration of 1mm and an optimal Mg(2+) concentration of 30 mm. At the optimal concentration, Mn(2+) was 4 times better than Mg(2+). The utilization of biosynthesized cytidine diphosphate diglyceride can be enhanced by addition of inositol, thereby causing the formation of phosphatidyl inositol.