Phospha tidylethanolamine

These pyridoxal-phosphate-dependent (or pyruvate-dependent) enzymes [EC 4.1.1.65] catalyze the decarboxylation of phosphatidyl-L-serine to produce phospha-tidylethanolamine and carbon dioxide. 

Leung, D., Saghatelian, A., Simon, G. M., and Cravatt, B. F. (2006). Inactivation of jV-acyl phospha-tidylethanolamine phospholipase D reveals multiple mechanisms for the biosynthesis of endocan-nabinoids. Biochemistry 45, 4720—4726. 

Phosphatidylcholine is synthesized via the Kennedy pathway (Kennedy and Weiss, 1956) in three consecutive steps catalyzed by the enzymes choline kinase, phosphocholine cytidyltransferase, and phosphocholine transferase. Phospha-tidylethanolamine is synthesized via the corresponding pathway for ethanolamine or by decarboxylation of phosphatidylserine (Borkenhagen et al., 1961) or by base exchange (Bjerve, 1973). In immobilized breast cancer cells, flux in these pathways... 

Changes in headgroup composition lipid class. A commonly observed change in lipid composition during thermal acclimation is a shift in the relative amounts of different classes of lipids present in a membrane. Cold acclimation frequently leads to an increase in phospha-tidylethanolamine (PE) and a decrease in phosphatidylcholine (PC). Thus, the PC/PE ratio falls, as shown for phospholipids isolated from gills of rainbow trout (Oncorhynchus mykiss) acclimated initially to either 5°C or 20°C and, then, transferred to the reciprocal temperature (figure 7.26 Hazel and Carpenter, 1985). The PC/PE ratio falls rapidly in the trout transferred to 5°C, and rises even more quickly in the trout transferred to 20°C. Note, however, that the PC/PE ratios did not reach stable plateau values during the 28-day acclimation period. Rather, after the initial rise (20° C) or fall... 

An X-ray structure of bovine heart cytochrome c oxidase at 2.8-A resolution showed eight phospholipid molecules, including five phospha-tidylethanolamines and three phosphatidylglycerols (Tsukihara et al.. 

Glenn et al. (1963) have observed that during the phase of accumulation of neutral lipids in rats given cerium (Snyder et al., 1959), a rare earth, an abnormal decrease of palmitate incorporation into phospha-tidylethanolamine occurs. The possibility that an abnormality of the metabolism of individual phosphatides may play a role in the development of fatty liver warrants further investigation. 

Fig. 4.8. Partial GC chromatogram of the acid-catalyzed methylated product of the isolated phospha-tidylethanolamine (PE) fraction from total beef heart lipids by fl-C (upper graph).The fatty acid methyl esters (FAME) and dimethylacetals (DMA) of total methylated PE were separated by TLC (solvent 3, Table 4.1) and analyzed using the same GC conditions.The last GC chromatogram represents the cyclic...

Phospholipids are important constituents of cell membranes and are of two kinds. Glycerophospholipids such as phosphatidylcholine and phospha-tidylethanolamine are closely related to fats in that they have a glycerol backbone esterified to two fatty acids (one saturated and one unsaturated) and to one phosphate ester. Sphingomyelins have the amino alcohol sphingosine for their backbone. 

AUen TM, Hong K, Papahadjopoulos D. Membrane contact, fusion, and hexagonal (Hll) transitions in phospha-tidylethanolamine Uposomes. Biochemistry. 1990 29(12) 2976-2985. 

Table 4. Desaturation of endogenous acyl-substrate in microsomal phospha-tidylethanolamine (PE) from the developing seeds of borage.

Initial stupes on the in vitro formation of cyclopropane fatty acids revealed that crude extracts of Serratia marcescens and C. butyricum catalyze the formation of cyclopropane fatly acids from S-adenosyl-methionine (Zalkin et al., 1963). Although no lipid or fatty acid requirement could be demonstrated for the reaction catalyzed by S. marcescens extracts, an absolute requirement for a phospholipid that contained an unsaturated fatty add was demonstrated with an extract of C. butyricum. Fvuihermore, the cyclopropane fatty acid formed in the reaction was shown to be one of the fatty acyl chains of phospha-tidylethanolamine. This surprising finding suggested that addition of the methylene bridge to the unsaturated fatty add occurred while the fatty acid was a component of the phospholipid molecule. The over-all reaction is shown in Fig. 11. 

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