Biosynthesis of phosphatidic acid from lysophosphatidic acid and palmityl coenzyme A.

In the preceding paper evidence was presented for the biosynthesis of lysophosphatidic acid from monoglyceride and adenosine triphosphate (1). Exogenous monoglycende was found to stim.ulate the formation of phosphatidic acid as well as lysophosphatidic acid. This observation suggested that lysophosphatidic acid was being converted to phosphatidic acid and therefore was functioning as an intermediate in the biosynthesis of phosphatidic acid from monoglyceride and adenosine triphosphate. In this paper it is shown that a chemically synthesized lysophosphatidic acid is acylated by S-palmityl coenzyme A to form phosphatidic acid in the presence of a cytoplasmic particulate fraction of guinea pig brain or liver. Lysophosphatidic acid is also degraded to glycerophosphate and orthophosphate by phosphatidases and phosphatases, respectively, in the enzyme preparation.