Phosphatidyl ethanolamine fatty acid composition

Kreps (1981) and his associates (Akulin et al., 1969 Chebotareva, 1983), in their studies on Far East sockeye salmon, found that the fatty acid composition of lipids in the food influences not only that of the triacyl-glycerols of the fish but also the phospholipid fraction. This comprises, firstly, the phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl serine and, secondly, the sphingomyelin and cardiolipin. All tissues except nervous tissue were found by these workers to be strongly influenced by the composition of the food. However, the fatty acids of the brain have also been found to change according to the diet in European bass (Pagliarani et al., 1986), the proportions of phospholipid to non-phospholipid being unaffected. 

The complex lipids in milk fat are comprised of the phosphoglycerides, phosphatidyl choline, phosphatidyl serine, phosphatidyl ethanolamine, phosphatidylinositol and plasmalogens. Also, the non-glyceride phospholipid, sphingomyelin, occurs in important amounts (Jensen, 2002). Bitman and Wood (1990) described the distribution of phospholipid classes in bovine milk and their fatty acid composition. The phospholipids comprise about 1% and cholesterol 0.4—0.5% of the total milk fat. These occur almost completely in the milk fat globule membrane. 

Fatty Acid Composition of Phosphatidyl-ethanolamine (PE) Fraction and Phosphatidylcholine (PC) Fraction in Yolk (% weight)... 

Fatty acid composition of phosphatidyl choline and phosphatidyl ethanolamine of wheat roots (12). 

Table 5. Fatty Acid Composition of Phosphatidyl Ethanolamine From Photoreceptor Membranes of Rats Raised on Various Diets...

Let us consider first lipid-lipid interaction. Urry et al, showed the existence of a positive CD band at 218 m/x and a negative CD band at about 192 m/z in phosphatidyl choline and phosphatidyl ethanolamine dissolved in trifluoroethanol (86). The 192-m/z band was not characterized in detail, but the 218-m/z band is of such position and shape that the addition of lipid and protein CD bands could produce a composite CD band, and hence an ORD Cotton effect, which is red shifted. As noted by Urry, the 218-m/z CD extremum of lecithin must arise from n — 7T transitions in the fatty acid ester groups. Although the optical activities of solutions of deproteinized membrane phospholipids determined at the same concentration as in the intact membrane are negligibly small, in membranes an ordered array of lipids could greatly enhance rotation. Such an effect could yield information on the nature of lipid-lipid association. This can be tested experimentally. Halobacterium cutirubrum offers a unique system since Kates has shown that the lipids in this extreme halophile contain ether bonds rather than ester bonds (43, 44), Hence, the n — tt transition essential to the CD band at 218 m/z in phospholipids does not exist. Nevertheless, we found that the ORD... 

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