Ganglioside Inner Esters
The glycosphingolipids are derivatives of N-acylsphingosines (ceramide) to which a carbohydrate unit, composed of one or more glycosyl moieties, is bound glycosidically in a β linkage to the hydroxyl at carbon 1 of sphingosine. The gangliosides are glyco-sphingolipids which contain one or more sialic acid residues as one of the glycosyl moieties (1). Gangliosides occur in most organs and body fluids but their highest concentration is in the central nervous system. The brain gangliosides are primarily located in neuronal dendritic processes and different brain areas have significantly different complements of the various gangliosides. Analyses of subcellular fractions have revealed that the ganglioside content of nuclei, mitochondria and synaptic vesicles is low while microsomes and synaptic membranes contain the highest amount of gangliosides. Thus gangliosides appear to be neuronal membrane components and perhaps participate in the complex molecular events at the synapse which are necessary for information processing. The combination of a large hydrophilic moiety with a strongly charged sialic acid and the hydrophobic ceramide portion suggest that gangliosides are membrane components which are suited for interaction with the microenvironment. It is possible that interaction of gangliosides with cations could lead to changes in the molecule which would in turn produce changes in the properties of the synaptic membrane. Calcium has a pronounced effect on the solubility of gangliosides. Reactions which would alter the number of negative charges in a ganglioside molecule such as formation of an ester could conceivably play an important role in modification of synaptic membrane properties.
KeywordsSialic Acid Glacial Acetic Acid DEAE Cellulose Synaptic Membrane Sialic Acid Residue
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- 1.H. Wiegandt, Angew. Chem. 1, 87 (1968).Google Scholar
- 2.J.E. Evans and R.H. McCluer, Fed. Proc. 30, 1133Abs (1971)Google Scholar
- 3.F. Snyder and N. Stephens, Biochim. Biophys. Acta 34, 214 (1959).Google Scholar
- 4.R.K. Yu and R. Ledeen, J. Biol. Chem. 21JL, 13(7 1969 ).Google Scholar
- 5.J.C. Speck in “Methods in Carbohydrate Chemistry” Vol. I, Ed. by Whistler and Wolfrom, Academic Press, N.Y. 1962, p. 441.Google Scholar
- 6.H. Wiegandt, Rev. Physiol. Biochem. Expt’l. Pharm. 2., 190 (1966).Google Scholar
- 7.E. McGuire and S.B. Binkley, Biochemistry 3, 247 (1964).Google Scholar
- 8.R. Kuhn and H. Muldner, Naturwissenschaften,51 635 (1964).Google Scholar