Animal Glycolipids and Gangliosides

An article on the biosynthesis of glycosphingolipids and tumourigenesis has reviewed the role of the Golgi apparatus in the synthesis of specific receptor 

Biochim. Biophys. Acta, 1976, 424, 98. 

The haemolytic activity of staphylococcal a-toxin was inhibited by the ganglioside (2) (containing a 2-acetamido-2-deoxy-D-glucosyl residue) from 

Keranen, M. Lempinen, and K. Puro, Clinica Chim. Acta, 1976, 70, 103. 

Sulpho-D-galactosylglycerolipid was barely detectable in brain tissue of rats up to 10 days of age but accumulated rapidly during the next 15 days and then remained at a fairly constant level. Most of the sulpho-o-galactosylglycero-lipid is in the myelin fraction and is present in a 1 1 mixture of the diacyl and alkylacyl forms. This lipid is synthesized from o-galactosyldiacylglycerol and adenosine 3 -phosphate 5 -sulphatophosphate.  

A higher concentration of ganglioside was found in the cerebrum and brain stem tissue of mice susceptible to audiogenic seizures than was found in resistant strains, but a lower concentration was found in the cerebellum. Of the individual gangliosides, a higher concentration of Gmi was found in all three regions of the brain of susceptible mice. 

The Gmi ganglioside jS-D-galactosidases from feline liver and brain have been purified and characterized. The preparation from brain tissue contained several isoenzymes whilst that from liver appeared to be homogeneous. The 

The structure of a novel L-fucose-containing ganglioside from pig cerebellum has been established (2). 9-O-Acetyl-A-acetylneuraminic acid accounts for up to 20% of the brain ganglioside fractions from man, cow, horse, pig, sheep, cat, rabbit, rat, chicken, and codfish. In the pig and cow, traces of the A-glycolyl derivative were also found. The novel trisialoganglioside, Giia (3), has been isolated and characterized and is responsible for 0.6% of the total ganglioside fraction of human brain.  

The ceramide trihexoside (6) accumulating in Fabry s disease has been synthesized by a conventional Koenigs-Knorr procedure. A novel ganglioside, disialosylparagloboside (7), has been isolated from human kidneys and its structure determined.  

The structures (1)—(5) of five gangliosides from human kidneys have been reported. The similarities in structure between the gangliosides (3) and (4) and blood-group substances of a glycosphingolipid nature were noted. 

Atzpodien and G. J. Kremer, J. Clin. Chem. Clin. Biochem., 1977, 15, 293. 

Fibroblasts from a patient with mucolipidosis I showed a five-fold increase in the level of sialic acid and a lower-than-normal level of lysosomal neuraminidase, which results in impaired catabolism of glycopeptides and glycolipids containing sialic acid. A D-mannosyltransferase has been found in suspensions of Balb/c fibroblasts incubated with GDP-D-[ C]mannose it appears to be present at the cell surface, where it is involved in the synthesis of glycolipids and glycoproteins.  

Gehler, and J. Spranger, Biochem. Biophys. Res. Comm., 1977, 74, 732. 

The cell-surface glycosphingolipids and other lipids in the fibroblasts from a family with familial hypercholesterolemia have been examined after they had been oxidized with D-galactose oxidase and then reduced with sodium borotritide. Comparisons of the radiolabel incorporated by homozygous, heterozygous, and normal fibroblast cells suggested that the defective metabolism of lipids in this disease is more extensive than previously realized. Gangliosides and asialo-G j have been shown to accumulate in the cerebrospinal fluid of a patient with SandhofTs disease.  

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Nonulosaminic acids are found as constituents of certain water-soluble, lipid fractions (glycolipids) of animal tissues, being particularly associated with gangliosides as well as with more complex lipopolysaccharides. The detection and characterization of the nonulosaminic acid component in these mucolipids has been based upon one or more of the color reactions (see below) applied to the macromolecular material, followed by isolation therefrom of methoxyneuraminic acid after methanolysis. The question of whether or not one or more acylated forms of neuraminic acid are actually present in the mucolipid has still to be resolved. Svennerholm has reported the isolation of A-acetylneuraminic acid from brain gangliosides. 

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