Phosphatidylcholine is a major component of very low density lipoproteins (VLDLs) secreted by the liver. Hepatic phosphatidylcholine is synthesized from choline via the CDP-choline pathway and from the phosphatidylethanolamine N-methyltransferase pathway. Elimination of the methyltransferase in male mice reduces hepatic VLDL secretion. Our objective was to determine whether inhibition of the CD...

A Saccharomyces cerevisiae strain deficient in phosphatidylethanolamine methyltransferase that exhibits choline auxotrophy grew in the presence of dioctanoyl phosphatidylcholine (diC8PC). We isolated and characterized mutants defective in growth in the diC8PC-containing medium. Mutations in LEM3/ROS3 impaired growth in that medium, indicating that Lem3p is involved in the utilization of extrace...

1. Distearoyl phosphatidylcholine and the phosphonium analogue, in which the nitrogen atom is replaced by phosphorus, show similar gel-liquid crystalline transition temperatures as detected by differential scanning calorimetry. 2. The temperature-dependence of the 31P n.m.r. (nuclear-magnetic-resonance) linewidths of the phosphate resonances of sonicated vesicles of distearoyl phosphatidylcholi...

The mechanism by which fatty acids stimulate the biosynthesis of phosphatidylcholine has been studied in cultured rat hepatocytes. Long chain fatty acids (1 mM) stimulated approximately 1.9-fold [methyl-3H] choline incorporation from phosphocholine into phosphatidylcholine by isolated hepatocytes. Oleate and palmitate (4 mM) enhanced phosphatidylcholine production by 3- and 2.2-fold, respective...

1. An artificial membrane system was formed by spreading at air/water and oil/water interfaces, by using phosphatidylcholine and the glycoprotein fetuin (mol.wt. 48400). 2. The plot of increase of interfacial pressure against amount of protein added beneath a monomolecular film of phosphatidylcholine showed two discontinuities, corresponding to the completion of two distinct layers of protein: ...