The enzymic formation of myoinositol 1:2-cyclic phosphate from phosphatidylinositol

Abstract

have indicated that mammalian tissues contain an enzyme that catalyses the degradation of phosphatidylinositol, producing a diglyceride and inositol monophosphate. Recent investigations have shown that with washed ram spermatozoa (Scott & Dawson, 1968) and extracts of pig thyroid tissue (Jungalwala, Freinkel & Dawson, 1971) the major water-soluble phosphate ester produced from phosphatidylinositol could be separated from inositol monophosphate by paper ionophoresis. This substance has now been identi- fied as inositol 1: 2-cyclic phosphate, and provided that precautions are taken to prevent its further breakdown its release can be demonstrated as a general property of the catabolic enzyme in all tissues.