Testicular Sterols

An enzyme that catalyzes the hydrolysis of prenol pyrophosphates was extracted from an acetone powder of testicular microsomes. The enzyme was partially purified by chromatography on diethylaminoethyl Sephadex. The partially purified enzyme catalyzed the hydrolysis of the phosphate ester bond of prenol pyrophosphates to yield equimolar amounts of prenol and inorganic pyrophosphate. Cleavage of inorganic pyrophosphate was catalyzed by a contaminating pyrophosphate phosphohydrolase that was present in crude preparations. The partially purified prenol pyrophosphate pyrophosphohydrolase catalyzed the hydrolysis of farnesol pyrophosphate, isopentenol pyrophosphate, and a mixture of biosynthetic 14C-prenol pyrophosphates, but hydrolysis of inorganic pyrophosphate, mevalonate-5-phosphate, β-glycerol phosphate, or adenosine triphosphate was not observed.