Ethanolamine Phosphatides Research Articles

Lipid composition of brain myelin from normal and hyperphenylalaninemic chick embryos

The influence of hyperphenylalaninemia on the lipid composition of brain myelin has been investigated in 19-day-old chick embryos. CNP-ase activity was used as myelin marker enzyme for myelin isolation. CNP-ase activity was significantly lower in hyperphenylalaninemic myelin when compared with control. No significant differences were observed after experimental treatment in the total lipid content of myelin as well as in the proportion of cholesterol:phospholipid:galactolipid. Nevertheless, a clear increase in the percentage of esterified cholesterol was found. No appreciable alterations were observed in the phospholipid composition of brain myelin from both control and hyperphenylalaninemic chick embryos. However, the ratio of unsaturated to saturated fatty acids in serine plasmalogen and sphingomyelin was considerably increased by this treatment. This ratio in choline and ethanolamine phosphatides from treated embryos did not differ from that of controls.

Novel quantitative method for determination of molecular species of phospholipids and diglycerides

A novel method is described for the quantitative analysis of subclasses (alk-1-enylacyl, alkylacyl, and diacyl types) and molecular species within each subclass of glycerophosphatides. Diradylglycerols from phospholipase C hydrolysis of the phospholipids are converted to benzoate derivatives, the benzoates are separated into their respective subclasses by thin-layer chromatography, and quantitated by measuring absorbance at 230 nm. Molecular species within individual subclasses are separated using a combination of argentation thin-layer chromatography and reversed-phase high-performance liquid chromatography with direct, on-line quantitation at 230 nm. We applied the method to the analysis of ethanolamine phosphatides from beef brain and were able to quantitate the three diradylglycerol subclasses (alk-1-enylacyl, alkylacyl, and diacyl types) as well as ca. 29 molecular species within each of these subclasses. This new quantitative approach for the analysis of specific molecular species of glycerolipids should be applicable to studies involving a variety of biologically important lipids, such as phosphatidylcholine, phosphatidylinositol, platelet activating factor, plasmalogens, and neutral type glycerolipids including diacylglycerols.

Interaction of lipids with intestinal brush border membrane preparations.

Conditions for uptake of lipids by rabbit intestinal brush border membrane preparations were investigated. A variety of lipids were found to be incorporated, including choline and ethanolamine phosphatides as well as cholesterol, diglyceride, and fatty acid. The incorporation of those lipids tested was enhanced by Ca2+ and other divalent cations but not by monovalent cations. The optimal Ca2+ concentration was approximately 10 mM. The uptake varied with lipid and membrane protein concentration and proceeded at rates which were too rapid to measure under several assay conditions tried. Incorporations were decreased substantially outside the pH range of 6.5-8.0. The effect of one lipid, phosphatidylcholine, on the structural appearance of the membrane fraction was examined by electron microscopy. No free or surface-bound lipid structures could be detected and the membrane fractions appeared to be unchanged after uptake.

Temperature adaptation of biological membranes. The effects of acclimation temperature on the unsaturation of the main neutral and charged phospholipids in mitochondrial membranes of the carp ( cyprinus carpio L.)

The phospholipid composition, fatty acid pattern and cholesterol content are studied in mitochondria of red lateral muscle of carp acclimated to high and low environmental temperatures. The results of the experiments are: mitochondria from cold-acclimated carp contain higher proportions of ethanolamine phosphatides than mitochondria from warm-acclimated fish, the opposite is true for the choline phosphatides. Thus, at constant pH, the membrane phospholipids are slightly more negatively charged at low acclimation temperature. The total plasmalogen content is reduced in the cold; this reduction is caused by a decrease in the proportion of the choline plasmalogens. The ethanolamine phosphoglycerides contain approx. 20% of the alk-1-enyl acyl type, irrespective of the acclimation temperature. There is no temperature-dependent difference in the low proportion of cholesterol. The fatty acids of total mitochondrial phospholipids are characterized by large amounts of the n-3 and n-6 families. The ratio of unsaturated to saturated fatty acids and the unsaturation index are remarkably higher than those reported for comparable mammalian phospholipids. Cold acclimation of carp does not significantly increase the unsaturation of total phospholipids. A fatty acid analysis of the main isolated phospholipids, however, shows that cold acclimation considerably increases unsaturation of the neutral phosphatidylcholine, whereas it dramatically decreases unsaturation of the negatively charged cardiolipin. It is suggested that the observed fatty acid substitution in phosphatidylcholine indicates a temperature-induced fluidity adaptation within the mitochondrial lipid bilayer, whereas the inverse acclimation pattern of cardiolipin provides a suitable lipid to accommodate the temperature-dependent modifications in the dynamic surface shape of integral membrane proteins.

Total lipid analysis of the sex pheromone gland of the redbanded leafroller moth, Argyrotaenia velutinana, with reference to pheromone biosynthesis

The total lipid complement of the sex pheromone gland of Argyrotaenia velutinana was analyzed. In addition to the pheromone components ( Z)-11-tetradecenyl acetate, ( E)-11-tetradecenyl acetate, and dodecyl acetate, the gland contained several glycerolipid classes with the analogous fatty acyl moieties ( Z)-11-tetradecenoic acid, ( E)-11-tetradecenoic acid and dodecanoic acid. These fatty acyl moieties were present only in the gland, in greater abundance than the pheromone components themselves, and were not observed in other tissues of the insect. They occurred principally in triglycerides, but were also found in choline phosphatides and ethanolamine phosphatides. The E Z ratio of the tetradecenoyl moieties was 61:39 in the triglycerides, 31:69 in the choline phosphatides, and 32:68 in the ethanolamine phosphatides, considerably different from the 9:91 ratio observed for the corresponding E and Z pheromone components. Reaction of the triglycerides with lipase indicated no selective distribution of the tetradecenoyl moieties among the sn-1, sn-2, and sn-3 positions. In contrast, reaction of the choline phosphatides with phospholipase A 2 indicated that tetradecenoyl moieties occurred exclusively at the sn-2 position. Pheromone components and tetradecenoyl and dodecanoyl moieties were found in trace amounts in glands of newly-eclosed females, but increased steadily in amount over the first few days after eclosion, implying concurrent biosynthesis of the pheromone components and the corresponding fatty acyl moieties, and implicating the fatty acyl moieties as probable intermediates in the biosynthesis of the sex pheromone components.

A comparative study of the glyceryl ether and other lipids of vertebrate lens

1. 1. Free alkyl glyceryl ethers were shown to be present in the lens of elevent species of vertebrates, from fish to man, in widely varying concentrations. 2. 2. Only rabbit lens had, in addition, free alkenyl glyceryl ether. 3. 3. The ethanolamine and lyso ethanolamine phosphatides isolated from adult human lens were shown to consist largely of the alkyl analogs. 4. 4. Free ceramides were detectable only in the lens of cat and adult man. 5. 5. Age related changes in phosphatides and other lipids of human lens are described.

The lipid composition of light and heavy myelin subfractions isolated from rabbit sciatic nerve

Centrifugation of adult rabbit sciatic nerve homogenates on continuous sucrose density gradients yields three distinct maxima at 0.12, 0.33 and 0.57 M sucrose (labeled A, B and C), respectively. Fraction A is absent in homogenates of immature rabbit sciatic nerve and the material isolated from adult animals is found to contain large amounts of triglycerides. It is proposed that fraction A results from the presence of adipose tissue adhering to the adult nerve preparations and should not be regarded as a true myelin subfraction. The concentration of the major membrane lipid classes (phospholipid, cholesterol and galactosyl ceramide) decreases from the light to the heavy side of the gradient. The ethanolamine phosphatide to sphingomyelin ratio increases from 1.06 to 1.42 between fractions B and C, due to an increase in the phosphatidal ethanolamine content at the expense of sphingomyelin.

Regulation of ethanolamine and choline phosphatide biosynthesis in isolated rat intestinal villus cells

The effects of ethanolamine, choline, and different fatty acids on phospholipid synthesis via the CDP-ester pathways were studied in isolated rat intestinal villus cells. The incorporation of [14C]glucose into phosphatidylethanolamine was stimulated severalfold by the addition of ethanolamine and long-chained unsaturated fatty acids, while the addition of lauric acid inhibited the incorporation of radioactivity into phosphatidylethanolamine. At concentrations of ethanolamine higher than 0.2 mM, phosphoethanolamine accumulated, but the concentrations of CDP-ethanolamine and the incorporation of radioactivity into phospatidylethanolamine did not increase further. The incorporation of [14C]glucose into phosphatidylcholine responded in a way similar to that of phosphatidylethanolamine, except that a 10-fold higher concentration of choline was required for maximal stimulation. CCC inhibited the incorporation of choline into phosphatidylcholine. In contrast with hepatocytes, villus cells did not form phosphatidylcholine via phospholipid N-methylation. The data indicate that, in intestinal villus cells, the cytidylyltransferase reactions are rate limiting in the synthesis of phosphatidylethanolamine and probably also of phosphatidylcholine. The availability of diacylglycerol and its fatty acid composition may also significantly affect the rate of phospholipid synthesis.

Isolation and characterization of plamsa membrane from monolayer cultures of epithelial type II lung cells

Pneumocyte type II produces a phospholipid, dipalmitoyl lecithin, which is stored in and secreted from the cell's inclusion bodies and is indispensable for alveolar stability. Cloned rat lung type II cells were harvested at monolayer confluence and homogenized in swelling buffer. After sequential differential centrifugations, the crude membrane fraction was subjected to discontinuous sucrose density gradient centrifugation at 65,000 × g. Quality of the relevant fractions was monitored by enzyme activities and phase contrast and electron microscopy of two major bands at densities 1.16 and 1.18, respectively. The less dense band contained only small quantities of organelles, little cytochrome c oxidase, and some glucose 6-phosphatase, but had a significant (Na +, K +)-ATPase activity; this and ultrastructural evidence certified the product as a suitable plasma membrane preparation. Upon sodium dodecyl sulfate-poly acrylamide gel electrophoresis, the protein pattern consisted of 11 major protein bands between 13,000 and 68,000 M r ranges, and several minor ones. The lipid pattern was studied by two-dimensional thin layer chromatograpy, followed by various group reactions (e.g., amine, unsaturation, phosphorus, sugars). In the two major phospholipids, phosphatidyl choline and phosphatidyl ethanolamine, palmitic acid was the least abundant of four major fatty acids, accounting for 14.20% in phosphatidyl choline and 5.70% in phosphatidyl ethanolamine, whereas the most abundant were stearic and palmitoleic with about 28% each in phosphatidyl choline, and palmitoleic (29.90%) and oleic (23.05%) in the ethanolamine phosphatide. Apparently, the palmitic acid containing phosphatidyl choline must be in the lamellar inclusion bodies of type II cells and not in their plasma membranes.

Influence of thermal acclimation on membrane lipid composition of rainbow trout liver

Rainbow trout (Salmo gairdneri) acclimated to 5 degrees C possessed larger livers and less neutral lipid per gram of liver than 20 degrees C-acclimated animals; quantities of liver glycolipid, phospholipid, and cholesterol did not vary significantly with acclimation temperature. The relative proportions of phosphatidylethanolamine increased significantly following cold exposure, whereas the quantities of sphingomyelin and cardiolipin declined. For all phosphatides examined (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysolecithin, cardiolipin, sphingomyelin) cold acclimation resulted in 1) an increase in the quantity of polyunsaturated fatty acids, 2) a reduction in the level of saturated fatty acids, and 3) little change in the total content of monoenes and dienes. The increased content of polyunsaturated fatty acids in choline and ethanolamine phosphatides following cold acclimation was confined to the 2-position and occurred at the expense of monoenes and dienes. The relative proportions of n - 3 fatty acids, and less frequently n - 6 fatty acids, increased in phosphatides of cold-acclimated trout, whereas the relative proportions of n - 9 fatty acids declined. These data suggest a preferential incorporation of fatty acids belonging to the linolenic acid family at reduced temperatures. Temperature-induced changes in the chemical composition of trout liver phospholipids counteracted the effects of acute temperature change on nonelectrolyte permeability of isolated liposomes.

Lipids from nerve tissues of the horseshoe crab, Limulus polyphemus

1. 1. The predominant lipids of nerve cords, ganglion and brain from horseshoe crabs were cholesterol (11% of lipid) and phospholipid (81% of lipid). 2. 2. Major phospholipids were phosphatidyl ethanolamine and phosphatidyl choline with lesser amounts of phosphatidyl serine and phosphatidyl inositol and sphingomyelin. 3. 3. The phospholipid fraction was characterized by a high content of plasmalogen, i.e. alk-1-enyl acyl phosphatides, so that 42% of the ethanolamine phosphatides were the plasmalogen, phosphatidal ethanolamine. 4. 4. Phosphatidyl choline and phosphatidyl ethanolamine were high in polyunsaturation with 20:4 and 20:5 major fatty acids. Sphingomyelin had predominantly long chain saturated fatty acids. 5. 5. Cerebrosides and gangliosides, which are associated with vertebrate nerve tissues, were absent from nerves of horseshoe crabs.

The Phospholipid Content of Ejaculated Fowl and Turkey Spermatozoa

Chicken and turkey spermatozoal lipids were separated into acidic and non-acidic fractions by DEAE cellulose column chromatography. The phospholipid composition of each fraction was examined by thin-layer chromatography, followed by phosphorus analysis.Chicken sperm phospholipid comprised 38.21% phosphatidyl choline, 9.04% phosphatidal choline, 12.62% phosphatidyl ethanolamine, 8.04% phosphatidal ethanolamine, 8.28% sphingomyelin, 9.76% phosphatidyl serine, 6.56% phosphatidyl inositol, and 7.49% cardiolipin.Turkey sperm phospholipid comprised 34.15% phosphatidyl choline, 7.14% phosphatidal choline, 15.61% phosphatidyl ethanolamine, 11.34% phosphatidal ethanolamine, 9.91% sphingomyelin, 8.83% phosphatidyl serine, 4.80% phosphatidyl inositol, and 8.22% cardiolipin.

Resolution of molecular species of intact serine and ethanolamine phosphatides by argentation chromatography of their trifluoroacetamides.

An effective resolution of intact phosphatidylserines on the basis of unsaturation has been achieved by conventional argentation thin layer chromatography (TLC) following trifluoracetylaction. The trifluoroacetamides are prepared by treatment with trifluoroacetic anhydride or N-methyl-bis-trifluoroacetamide. The acetamides are resolved with chloroform-methanol-water (65:25:4, v/v/v) on Silica Gel G containing 20% silver nitrate. Subfractions with 0-6 double bonds per molecule were obtained for the phosphatidylserines of pig and ox brain, pig erythrocytes, rat liver, and rabbit skeletal muscle. The preparation of trifluoroacetamides is also advantageous for the silver ion fractionation of phosphatidylethanolamines. The method is applicable to metabolic studies of molecular species using radioactive precursors of neutral lipids, phosphorus, and nitrogenous bases.

In vivo incorporation of exogenous stearic acid in synaptosomes: High occurrence of non-esterified fatty acids

Subcutaneously injected stearic acid is taken up by the brain through the ‘blood-brain barrier’ and is incorporated into synaptosomal lipids (as well as into other brain compartments). Phospholipids are potent acceptors (choline phosphatides, ethanolamine phosphatides, serine phosphatides). Moreover a high level of radioactivity was found in non-esterified fatty acids.

The lipids of buffalo spermatozoa and seminal plasma

Lipids were extracted from the spermatozoa and seminal plasma of buffalo and were analysed by column and thin-layer chromatography. Buffalo spermatozoa (10(9) cells) contained 1-15 mg total lipids, 0-285 mg neutral lipids, 0-396 mg glycolipids, 0-547 mg phospholipids and 0-015 mg gangliosides. The corresponding values for 1 ml seminal plasma were: 1-50, 0-439, 0-581, 0-594 and 0-010 mg. The sperm neutral lipids were comprised of 3-2% hydrocarbons, 4-5% cholesterol esters, 46-7% triglycerides, 17-5% 1,3-diglycerides, 3-1% 1,2-diglycerides, 17-6% cholesterol, 0-6% free fatty acids and 2-4% monoglycerides. The corresponding values for seminal plasma were: 4-2, 6-2, 33-0, 19-8, 4-2, 18-5, 3-8 and 4-7%. In the sperm phospholipids, there was 30-4% phosphatidyl choline; 19-4% phosphatidal choline; 10-8% phosphatidyl ethanolamine; 3-4% phosphatidal ethanolamine; 11-3% sphingomyelin; 1-5% phosphatidyl serine; 0-6% phosphatidyl inositol; 3-9% lysophosphatidyl choline; 4-4% lysophosphatidyl ethanolamine; 0-7% lysophosphatidyl serine; 5-5% diphosphatidyl glycerol and 0-3% phosphatidic acid. The corresponding values for seminal plasma were: 21-7, 17-3, 11-7, 4-1, 13-1, 2-8, 3-9, 5-6, 1-0, 7-4 and 0-5%. Comparative data for bull spermatozoa and seminal plasma were also obtained.

THE ISOLATION AND LIPID COMPOSITION OF MYELIN‐FREE AXONS FROM RAT CNS1

Abstract—Myelin‐free axons were isolated from rat CNS using a modification of the method of De Vrieset al. (1972). On a dry weight basis, the axons contained 15·2% lipid composed of 19·4% cholesterol, 56·9% phospholipid and 23·7% galactolipid with a weight ratio of cerebroside to sulfatide of 3·6‐1. The phospholipid was composed of 11·0% ethanolamine phosphatides (44·4% in the plasmalogen form), 21·0% choline phosphatides (9·3% in the plasmalogen form), 4·5% sphingomyelin, 4·5% phosphatidyl serine, 4·3% phosphatidyl inositol, 3·0% diphosphatidyl glycerol and 8·5% unidentified phospholipid. The rat axons contained 0·18 μg ganglioside NeuNAc/mg dry wt. In addition to the 4 major brain gangliosides, the rat axons contained gangliosides GD2 and GD3. The axonal galactolipid could not be accounted for by myelin contamination as revealed by electron microscopy, absence of the characteristic ratio of myelin specific proteins in the axonal protein profile as shown by polyacrylamide gel electrophoresis, and the axonal level of the myelin marker enzyme 2′,3′‐cyclic nucleotide‐3′‐phosphohydrolase. The relationship between lipids of axons isolated from rat and bovine CNS, and rat whole brain and CNS myelin is discussed.

Comparative studies on the lipid composition of some digenetic trematodes

Yusufi A. N. K. & Siddiqi A. H. 1976. Comparative studies on the lipid composition of some digenetic trematodes. International Journal for Parasitology 6: 5–8. Neutral lipids and phospholipids of six digenetic trematodes, Cotylophoron cotylophorum, Gastrothylax crumenifer and Gigantocotyle explanatum from water buffalo, Echinostoma malayanum and Fasciolopsis buski from pig and Isoparorchis hypselobagri from cat-fish were analyzed. Total lipid concentrations in trematodes varied considerably irrespective of their hosts and habitats. While triglycerides were the major components in all species, considerable amounts of phospholipids and free fatty acids were present in all species. Cholesterol was minimum (4–9%) in more or less all species, except in F. buski, where cholesterol, phospholipids and triglycerides constituted 13–14% and free fatty acids around 7%. Among phospholipids, choline and ethanolamine phosphatides were major polar lipids. Sphingomyelin and cardiolipin were present as small fractions and lysophosphatidylcholine was evenly distributed among all the species (9–12%) except in F. buski, which contained a little higher content (15%).

Distribution of Newly Formed Palmitate and Stearate Among Molecular Species of Choline and Ethanolamine Phosphatides

The choline and ethanolamine phosphatides derived from isolated rat livers during perfusion with 75 percent deuterated water (Kuksis, A., Myher, J.J., Marai L., Yeung, S.K.F., Steiman, I. & Mookerjea, S. (1975) Can. J. Biochem. 53, 509-518) were resolved into molecular species by argentation thin-layer chromatography. The time course of percentage replacement of the newly synthesized fatty acids in each molecular species was determined by gas chromatography with mass spectrometry. The results confirmed the earlier postulated differential utilization of palmitic and stearic acids in glycerolipid biosynthesis as well as supported the hypothesis of a precursor-product relationship between the oligoenoic and tetranoic species of both phosphatides. Calculations of half-lives gave values of 14-19 h for palmitoyl oligoenes, 40-50 h for palmitoyl tetraenes, and 22-28 h for palmitoyl hexaenes of both choline and ethanolamine phosphatides. The corresponding stearoyl species had half-lives which ranged from 89 to 200 h. Evidence was obtained for a metabolic heterogeneity among subsets of molecular species recognized on the basis of combinations of new and old glycerol and fatty acids in the same glycerolipid molecule.

Distribution of newly formed fatty acids among glycerolipids of isolated perfused rat liver.

Livers of chow fed rats were perfused 1-3 h with buffer, glucose, albumin, and red blood cells, made up in 100 percent D(2)O. Glycerolipids were isolated and the deuterated fatty acids determined by gas chromatography with mass spectrometry on Silar 5 CP. Percentage of replacement by deuterated acids ranged from 1 to 14, of which palmitate was 87 percent. Differences were found in total lipid class and in subcellular distribution of the newly synthesized acids. Microsomes had 37 percent more deuterated acids than the total or floating fat. At 3 h the highest replacement was found in diacylglycerols (17 percent) and free fatty acids (11 percent). Of the palmitate in hepatic choline and ethanolamine phosphatides, 6.9 percent and 4.7 percent, respectively, contained dueterium. The serine and inositol phosphatides had a higher proportion of deuterated palmitate (7.7 percent) than other phosphatides. The data support the hypothesis that palmitate is incorporated into glycerolipids largely via de novo synthesis while stearate enters them by deacylation-acyl transfer replacement.

Phospholipids of goat spermatozoa and the seminal plasma.

Phospholipids of goat spermatozoa and seminal plasma were separated and quantified by two dimensional thin layer chromatography. The spermatozoal phospholipids were comprised of 25.0 percent phosphatidyl choline, 27.8 percent phosphatidal choline (choline plasmalogen). 5.0 percent phosphatidyl ethanolamine, 0.9 phosphatidal ethanolamine (ethanolamine phasmalogen), 11.8 percent sphingomyelin, 2.8 percent phosphatidyl serine, 1.8 percent phosphatidyl inositol, 4.4 percent lysophosphatidyl choline. 4.3 percent lysophosphatidyl ethanolamine, 8.0 percent diphosphatidyl glycerol (cardiolipin) and 0.5 percent phosphatidic acid. The corresponding values for the seminal plasma phospholipids were 18.3, 19.1, 9.1, 3.0, 15.0, 4.1, 3.5, 5.5, 9.6, 2.0 and 0.7 percent, respectively.