A sensitive radioactive assay of acyl CoA:sn-glycerol-3-phosphate-O-acyltransferase (EC 2.3.1.15) was developed to study the properties and subcellular distribution of this enzyme in rat epididymal adipose tissue. The esterification of sn-glycerol-3-phosphate was measured in the presence of palmitoyl CoA or palmitate, ATP, CoA, and Mg(2+) at pH 7.5. The presence of glycerophosphate acyltransfer...

The Saccharomyces cerevisiae DPP1-encoded diacylglycerol pyrophosphate phosphatase catalyzes the dephosphorylation of diacylglycerol pyrophosphate to form phosphatidate and Pi. The enzyme also dephosphorylates phosphatidate to form diacylglycerol and Pi. Because diacylglycerol pyrophosphate, phosphatidate, and diacylglycerol have roles as lipid signal molecules in higher eukaryotic cells, it is...

The regulation of purified yeast membrane-associated phosphatidylserine synthase (CDP-diacylglycerol:L-serine O-phosphatidyltransferase, EC 2.7.8.8) and phosphatidylinositol synthase (CDP-diacylglycerol:myo-inositol 3-phosphatidyltransferase, EC 2.7.8.11) activities by phospholipids was examined using Triton X-100/phospholipid mixed micelles. Phosphatidate, phosphatidylcholine, and phosphatidyl...

The initiation of receptor-mediated small artery contraction is dependent on inositol 1,4,5-trisphosphatestimulated release of stored calcium. The role of the other product of inositol lipid hydrolysis, 1,2-diacylglycerol, in maintaining contraction remains controversial. Therefore, we have determined the contractile response of rat subcutaneous small arteries (<300 ,m i.d.), when mounted as ri...

Kidney glucose 6-phosphatase has been shown to catalyze inorganic pyrophosphatase and inorganic pyrophosphate-, cytidine diphosphate-, cytidine triphosphate-, and mannose 6-phosphate-glucose phosphotransferase reactions. The catalytic properties of phosphohydrolase and phosphotransferase activities of the kidney enzyme were found to be very similar to those of corresponding hepatic activities (...

A nucleotide phosphohydrolase (adenosine triphosphatase), which is associated with vaccinia virus cores, has been solubilized and shown to be deoxyribonucleic acid dependent.

1. The activities of fatty acid synthetase, acyl-CoA synthetase, glycerol phosphate acyltransferase and phosphatidate phosphatase were measured in the mammary glands of rabbits from day 16 of pregnancy to day 15 of post partum. 2. There were significant correlations between the increases in activities of these enzymes during this period. This was the case whether the activities were expressed p...

The phosphatidate-synthesizing system of rat-liver microsomes was resolved into two component enzymes, glycerolphosphate acyltransferase and 1-acylglycerolphosphate acyltransferase. The resolution is effected by sucrose density gradient centrifugation in the presence of a nonionic detergent, Triton X-100. Combination of both enzymes results in reconstitution of the phosphatidate-synthesizing sy...