Brain lipids gangliosides

Myelin is approximately 75% lipid and 25% protein. Carbohydrate residues are associated with both the lipid and the protein components of myelin. High proportions of cholesterol, phospholipid, and glycolipid are found in the lipid fractions. Phospholipids include ethanolamine phosphatides, phosphatidylserine, and phosphatidylinositol glycolipids include both neutral (cerebroside, sulfatide, galactosyldiglyceride) and polar (gangliosides, especially GMj and GMJ lipids. A classification and discussion of the metabolism of brain lipids is beyond the scope of this article readers are referred to Lajtha (1969), Davison (1968), Awasthi and Srivastava (1980), and Suzuki (1981). 

When ceramide combines with oligosaccharides and N-acetylneuraminic acid (NANA, also known as siaUc acid), the gan-gliosides are formed. Gangliosides comprise approximately 5% of brain lipids. 

The biochemical buildup of the brain is far from complete at birth, and the biosynthesis of brain lipids is essential to the proper development of the child. Among the lipids found in brain are gangliosides, cerebrosides, and sphingomyelins. The synthesis of these lipids assumes particular importance when the nerve... 

Studies on brain lipids in Tay-Sachs disease. II. Solubility properties of gangliosides. 

The book has been written to provide a hands-on approach for neuroscience graduate students. Biochemical structures are dissected and explained with molecular models. Moreover, we propose a step-by-step guide to memorize and draw the biochemical structure of brain lipids, including cholesterol and complex gangliosides. To conclude the book, we present new ideas that can drive innovative tiierapeutic strategies based on the knowledge of the role of lipids in brain disorders. 

Materials. Egg phosphatidylcholine (PC), bovine brain phosphatidylserine (PS) were obtained from Avanti Polar Lipids Inc. (Birmingham, AL) and cholesterol was from Sigma (St. Louis, MO). Ganglioside GMj, bovine, was obtained from Calbiochem (San Diego, CA). Diethylenetriamine pentaacetic acid distearylamide complex (DPTA-SA) was synthesized according to ref. 17 and nlIn-DTPA-SA was prepared as described (7). This lipophilic radiolabel is not transferred to the serum components from liposomes (unpublished data), nor is it rapidly metabolized in vivo (7). The synthesis of N-(glutaryl)phosphatidylethanolamine(NGPE) has been described (18). Dipalmitoyl deoxyfluorouridine(dpFUdR) was synthesized as described (24). 

Among the important glycolipids, which are combinations of carbohydrate and lipid, are the cerebrosides and gangliosides. These are constituents of brain and nervous tissue and are usually considered with lipids because they are water-insoluble. Water-soluble polymers of high relative molecular mass containing lipid and carbohydrate, known as lipopolysaccharides, are found in bacterial cell walls. 

Analysis of I-cell patient glycosphingolipids reveals elevations in trihexosylceramide (GL-3) and the ganglioside GM3 (Fig. 17-3) but not the massive accumulation associated with the glycosphingolipidoses. In the spleen, the only apparent lipid abnormality is an increase in the level of GMj. The brain has normal levels of gan-gliosides, apart from a small increase in GM3 and... 

Tay-Sachs disease, the lipid storage disease that afflicts 1 in 900 children of Ashkenazic Jewish parents, results in the accumulation of the ganglioside ceramidc-/3-glucose-/3-galactose-A-acetylgalactosamine /V-acetylneuramic acid in the brain. Why does this occur ... 

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