Gangliosides fatty acids

The ganglioside fatty acids in TSD consist of 85% stearic acid, 4.5% myristic acid, 6.6% arachidonic acid, and 1.6% behenic acid (Klenk et al. 1963). The nomenclature of gangliosides is outlined in table 1. 

Ganglioside fatty acids were analyzed repeatedly in TSD (Klenk 1942, 1955, SvENNERHOLM 1957 b, Klenk and Gielen 1961a, b, Svennerholm and Raal 1961, Klenk et al. 1963) and no significant differences from the normal pattern were observed (Rouser et al. 1965). 

Fig. 14.—Schematic Representation of the Fragmentation Observed in the Positive F.a.b.-Mass Spectrum of a Permethylated Ganglioside Isolated from Granulocytes. [Other glyco-sphingolipids fragment in a similar way. Major cleavages are shown with solid lines, and minor cleavages with dotted lines. The masses of ions resulting from cleavages (a), (b), and (c) define the type of sphingosine and the type of fatty acid. In this example, (a) is 548, (b) is [M + H] minus 238, and (c) is [M + H] minus 533.]...

Hydrophobic and Hydrophilic Components of Membrane Lipids A common structural feature of membrane lipids is their amphipathic nature. For example, in phosphatidylcholine, the two fatty acid chains are hydrophobic and the phosphocholine head group is hydrophilic. For each of the following membrane lipids, name the components that serve as the hydrophobic and hydrophilic units (a) phos-phatidylethanolamine (b) sphingomyelin (c) galactosyl-cerebroside (d) ganglioside (e) cholesterol. 

Butyrate appears to have its most profound effects on neoplastic cells such as HeLa in addition to morphological and biochemical differentiation, the fatty acid inhibits cell growth (2). Previous studies have established a correlation between decreased ganglioside synthesis and malignant transformation (43-46). Transformed baby hamster kidney and newborn rat kidney cells exhibited a loss of GM3 and sialyl transferase activity (43,44). 

The apolar chains of the ceramide portion of gangliosides are responsible for the hydrophobic properties of gangliosides and for their availability to hydrophobic interactions. The formation of an hydrogen bond between the 3-hydroxyl group of the sphingo-sine and the carbonyl oxygen of the fatty acid, would tend to spread the two hydrocarbon chains reducing their tendency for mutual association, and thus to promote association of each chain with other molecules ( 3 ). 

Palmitic acid was present in all thymus gangliosides as a major fatty acid, which is also in contrast to the fatty acid compositions of the various organs. 

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