the limiting step in phosphatidylcholine biosynthesis was the formation of cdp-choline catalyzed by ctp : choline-phosphate cytidylyltransferase ( ec 2.7.7.15 ) as monitored by the decrease in phosphocholine labeling following phospholipase c treatment of cells prelabeled with [ 3h ] choline .
C0031716
phosphocholine
C0008405
choline