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Phosphatidylethanolamine analogs

Phosphatidylethanolamine synthesis begins with phosphorylation of ethanol-amine to form phosphoethanolamine (Figure 25.19). The next reaction involves transfer of a cytidylyl group from CTP to form CDP-ethanolamine and pyrophosphate. As always, PP, hydrolysis drives this reaction forward. A specific phosphoethanolamine transferase then links phosphoethanolamine to the diacylglycerol backbone. Biosynthesis of phosphatidylcholine is entirely analogous because animals synthesize it directly. All of the choline utilized in this pathway must be acquired from the diet. Yeast, certain bacteria, and animal livers, however, can convert phosphatidylethanolamine to phosphatidylcholine by methylation reactions involving S-adenosylmethionine (see Chapter 26). [Pg.821]

Martin, O.C. and Pagano, R.E., 1987, Transbilayer movement of florescent analogs of phosphatidylserine and phosphatidylethanolamine at the plasma membrane of cultured cehs. /. Biol. Chem., 2lSl 5890-5898. [Pg.57]

Although the role of lipid composition in membrane function is not entirely understood, changes in composition can produce dramatic effects. Researchers have isolated fruit flies with mutations in the gene that encodes ethanolamine kinase (analogous to choline kinase Fig. 21-28). Lack of this enzyme eliminates one pathway for phosphatidylethanolamine synthesis, thereby reducing the amount of this lipid in cellular membranes. Flies with this mutation—those with the genotype easily shocked—exhibit transient paralysis following electrical stimulation or mechanical shock that would not affect wild-type flies. [Pg.813]

The methodology used here for structure proof of phosphatidylethanolamine (and its analogs) is very similar to that described in Chapter 4 for phosphatidylcholine (and its analogs). Consequently a more limited discussion of the procedures and protocols for phosphatidylethanolamine will be undertaken... [Pg.137]

Phosphatidylethanolamines, or cephalins (so-called because they were first obtained from brain tissue), can be synthesized by reactions analogous to those of de novo synthesis of phosphatidylcholine. Ethanolamine is first phosphorylated by ATP and ethanolamine kinase to phosphoethanolamine, which then reacts with CTP to form CDP-ethanolamine. CTPrphosphoethanolamine cytidylyltransferase is not located on the endoplasmic reticulum, nor do fatty acids activate it as they do the analogous enzyme of phosphatidylcholine synthesis. Finally, 1,2-diacylglycerol phosphoethanolamine transferase catalyses the reaction of diacylglycerol with CDP-ethanolamine to form phosphatidylethanolamine. [Pg.402]

The most common phospholipid in mammals is phosphatidylcholine. In this case, dietary choline is activated in a series of reactions analogous to those in the activation of ethanolamine. Interestingly, the liver possesses an enzyme, phosphatidylelhanolamine methyltransferase, that synthesizes phosphatidylcholine from phosphatidylethanolamine when dietary choline is insufficient. I he amino group of this phosphatidylethanolamine is methylated three times to form phosphatidylcholine. S-Adenosylmethionine is the methyl donor. [Pg.736]

Ceramides are intracellular signaling molecules implicated in the induction of cellular apoptosis (Kolesnick and Krbnke, 1998 Hannun and Luberto, 2000), and are known to induce several protein kinases and phosphatases (Mathias et al., 1991 Dobrowsky et al., 1993 Vietor et al., 1993). Ceramide analogs have been shown to inhibit PC synthesis (Bladergroen et al., 1999 Allan, 2000 Ramos et al., 2000 Vivekananda et al., 2001). Ceramides may directly affect the biosynthesis of PC and phosphatidylethanolamine (PE) by inhibiting the enzymes of the CDP-choline and CDP-ethanolamine pathways (Bladergroen et al., 1999 Awasthi et al., 2001 Ramos et al., 2002). [Pg.258]

The ability to disperse phospholipids in water is related to the melting transition temperature of the hydrocarbon chains. (An analogous situation is observed with soaps, where the ability to disperse occurs only above a temperature which is nearly constant over a wide range of concentrations and varies with the chain length.) At room temperature the fully saturated phospholipids cannot readily be dispersed in water. On the other hand, the natural unsaturated phospholipids disperse readily (16). Raising the temperature increases the dispersibility of the fully saturated phosphatidylethanolamines. [Pg.172]

Phosphatidylethanolamine is usually synthesized from phosphatidic acid or from iodohydrin diesters. The analogous route to that of phosphatidylcholine from glycerophosphorylcholine is not usually used because it is difficult to obtain the substrate in a sufficiently pure state. Care must be taken during the synthesis of phosphatidylethanolamine to protect the unsubstituted amino function. [Pg.303]

The synthesis of ether phosphatidylethanolamines is analogous to that for the formation of the corresponding phosphatidylcholines (Rosenthal, 1975). The iV-methyl-and AW-dimethyl derivatives have been synthesized from their corresponding phosphatidic acids (Aneja et aL, 1970). The formation of AT-acylphosphatidylethanolamines and other analogues is detailed by Slotboom and Bonsen (1970) and that of ethanolamine plasmalogens in Section 7.5.8. [Pg.304]

Analogous to normal phase HPLC, CE has been successfully used for separation of the various types of phospholipids phosphatidylcholine, phosphatidylethanolamine, phos-phatidylserine, phosphatidylinositol, and phosphatidic acid. The elution order is affected by buffer strength and composition. Analogous to reversed-phase HPLC, some separation according to the nature of the fatty acid substituents is seen with MEKC. [Pg.418]

Phosphatidylethanolamine can also be formed by an analogous series of reactions to phosphatidylcholine that is by the successive actions of ethanolamine kinase, ethanolamine phosphate cytidylyltransferase and ethanolamine phosphotransferase (Figure 7.1). As in the synthesis of phosphatidylcholine, the activity of the cytidyltransferase appears to be rate limiting for phosphatidylethanolamine synthesis and also the final enzyme, the ethanolamine phosphotransferase, catalyses a freely reversible reaction. [Pg.299]


See other pages where Phosphatidylethanolamine analogs is mentioned: [Pg.825]    [Pg.35]    [Pg.43]    [Pg.44]    [Pg.52]    [Pg.813]    [Pg.291]    [Pg.41]    [Pg.18]    [Pg.44]    [Pg.52]    [Pg.269]    [Pg.255]    [Pg.181]    [Pg.813]    [Pg.259]    [Pg.382]    [Pg.139]    [Pg.61]    [Pg.236]    [Pg.161]    [Pg.30]    [Pg.108]   
See also in sourсe #XX -- [ Pg.115 ]




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Phosphatidylethanolamine

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