Chibnall and Channon, investigating the cytoplasma of cabbage and spinach leaves (I), isolated a mixture of substances which resembled monophosphatides in their structure and composition, but mere virtually free of nitrogenous bases. The main constituents were identified as the calcium, magnesium, and potassium salts of phosphoric acid esters of diglycerides. These compounds, constituting a new...

Phosphatidic acid or 1,2-diacyl-sn-glycero-3-phosphate is not an abundant lipid constituent of any living organism to my knowledge, but it is extremely important as an intermediate in the biosynthesis of triacylglycerols and phospholipids and as a signalling molecule. Indeed, it is often over-estimated in tissues as it can arise by inadvertent enzymatic hydrolysis during inappropriate storage o...

1. The presence of palmitoyl-CoA-l-glycerol 1-phosphate palmitoyltransferase (EC2.3.1.15) has been demonstrated in a particulate fraction of baker's yeast. 2. The enzyme has been characterized, and its activity studied as a function of pH and concentration of substrates. 3. Inhibition by thiol poisons and protection by acyl-CoA have been used to obtain information on the active site. 4. By vari...

In 1941 Pangborn (1) reported the isolation of a complex phosphatidic acid from beef heart and suggested the name cardiolipin for it. The presence of this phospholipide seems to be essential for the complementbinding activity of beef heart extracts with sera of syphilitic patients. On hydrolysis (2) with ethanolic potassium hydroxide at room temperature the phosphatidic acid yielded, in additio...

Intraperitoneal injection of maximally effective doses of corticotropin(1-24) [ACTH(1-24)] provoked maximal increases in rat adrenal phospholipids as follows: phosphatidic acid within 1.5-2 min, phosphatidylinositol and phosphatidylglycerol within 4-6 min, and polyphosphoinositides and corticosterone within 5-15 min. Continued maximal adrenal stimulation by ACTH(1-18) treatment caused sustained...

The alveoli of the mammalian lung are lined by a film of surface-active material (surfactant) which is commonly believed to be a phospholipid (1, 5, 8, 11) . A considerable body of evidence has accumulated which suggests that surfactant is synthesized by the granular pneumonocytes (type II cells) of the alveolar epithelium (1, 9, 10) . Although a number of acid hydrolases have been demonstrated...

A highly active phospholipase D that is specific for cardiolipin was detected in the gram-negative bacterium Haemophilus parainfluenzae. Previously reported phospholipase D preparations have come exclusively from higher plants. The bacterial enzyme hydrolyzed cardiolipin to phosphatidyl glycerol and phosphatidic acid. During the incubation, phosphatidic acid disappeared. Phosphatidyl ethanolami...

Diacylglycerol kinases (DGKs) phosphorylate diacylglycerol to form phosphatidic acid. In most cases, members of this large family of enzymes appear to bind and regulate proteins activated by either diacylglycerol or phosphatidic acid. Proteins that appear to be regulated, in part, by DGKs include protein kinase Cs, RasGRPs, and phosphatidylinositol kinases. By modulating the activity of these p...