Lysophosphatidyl ethanolamine

For calculation it was assumed that these five phospholipids together accounted for all of the phospholipids of the membrane. In the actual analyses, other phospholipids (primarily lysophosphatidyl choline and lysophosphatidyl ethanolamine) were found to account for less than 5% of the total. The heavy and light microlipid droplet fractions were obtained by sucrose density gradient centrifugation. Heavy fractions were collected between 0.5 and 1.0 M sucrose and light fractions banded at the 0.5 M sucrose-buffer interface. 

Figure 8.2.2 A. Py-CH4 Cl MS spectrum Figure 8.2.2 B. Py-CH Cl MS spectrum of lysophosphatidyl ethanolamine [9], obtained at 217.6f C from a lipid extract of...

As seen in Figures 8.2.2 A and 8.2.2 B, the two spectra have significant similarities indicating the presence of lysophosphatidyl ethanolamine in the lipid extract. The lysophosphatidyl ethanolamine (lysocephalin) can be obtained from an appropriate material (egg yolk, bovine liver, or bovine brain) using a phospholipase. The fatty acids in this lysophosphatidyl ethanolamine are primarily palmitic and stearic acids. 

LPC, lysophosphatidylcholine PC, phosphatidylcholine LPE, lysophosphatidyl-ethanolamine PI, phosphatidylinositol PA, phosphatidic acid PE, phosphatidyl-ethanolamine. 

Lysophosphatidyl-ethanolamine One mole of fatty acid/mole of lipid Trace lipid in animals, plants, and microorganisms... 

Lyso-glycerophospholipids Another widely distributed class of lipids, which occurs only in small amounts, is comprised of the lyso-phosphatidyl cholines and lyso-phosphatidyl ethanolamines. These compounds are formed in normal tissue by the action of phospholipase A on phosphatidyl choline and phosphatidyl ethanolamine. The enzyme attacks the fatty acid ester bond in the /3-position, splitting off a monoenoic or polyenoic fatty acid (Tattrie 1959 Hanahan 1960). The naturally occurring a -acyl residues are predominantly saturated. The structures of lysophosphatidyl choline and lysophosphatidyl ethanolamine are given in the following figures ... 

As stressed for the biosynthesis of lecithin, the possibility of alternative pathways should be borne in mind. An example is the demonstration by Mebkl and Lands (1963) of the enzymic acylation of lysophosphatidyl ethanolamine to form phosphatidyl ethanolamine by a reaction similar to that described for the acylation of lysolecitW to form lecithin (Reaction 16). 

Although the nuclear membrane s proteins have been fractionated by gel electrophoresis and their amino acid composition has been studied, their function remains unknown. However, it is certain that they are not histones. Although the quantitative content of phospholipids in the nuclear membrane is not certain, it is estimated that 50-60% of the phospholipids found in the nucleus are associated with the membrane. They include cardiolipin, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, phosphatidyl choline, sphingomyelin, and lysophosphatidyl choline. Of course, as in most cellular membranes, their function remains to be determined. 

Like glycolipids, phospholipids are also a elass of polar lipids. Data in Table 3.2 show that phospholipids in natural rubber are normally below 0.6% w/w. A recent study showed that the major components were phosphatidyl choline (PC) and lysophosphatidyl choline (LPC), as shown in Table 3.5. Other minor components were phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), lysophosphatidyl inositol (LPI), and metal phosphatidates (MP) or phosphatidic acid (PA). Unlike neutral lipids and glycolipids, the acyl components of phospholipids normally contain very low levels of furanoic acid, except for certain rubber clones. The isolated fatty acids are mainly palmitic, stearic, oleic and linoleic acids. ... 

From the standpoint of practical TLC, this chapter considers the following simple hpids free sterols acyl-, diacyl-, and triacylglycerols free fatty acids methyl esters sterol esters and the following polar lipids phosphatidyl choline, lysophosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, sphingoipyelin, cerebrosides, and sulfatides. 

The phospholipid spray tests should be done along with Experiment 3. The phosphate test will produce very distinct blue spots with the following phospholipids lysophosphatidyl choline, phosphatidyl serine, phosphatidyl choline, and phosphatidyl ethanolamine. The ninhydrin test will produce purple spots only with phosphatidyl serine and phosphatidyl ethanolamine. 

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