Studies on Brain Tissue of Tay-Sachs' Disease. Iv. Partitioning of Gangliosides into a Chloroform-Rich Phase
Journal of Neurochemistry 12: 311-321
ISSN/ISBN: 0022-3042 PMID: 14336231 Accession: 025555221
Gangliosides from brain tissue of patients with Tay-Sachs' disease could be removed from their solution in aqueous media and partitioned in a chloroform-rich phase. This occurred upon addition of any one of the following components to the biphasic system of Folch et al.: an anionic lipid and low concentration of a monovalent salt, such as KC1; a cationic lipid in the absence of salt; higher concentrations of KC1; low concentrations of salt with a di- or polyvalent cation. The same effect was also obtained when the carboxylate ion of the sialic acid residue was blocked by methylation or its dissociation was suppressed at low pH. These effects were compared with gangliosides from nonpathological human brain; in all cases, the latter exhibited a higher relative solubility in the polar medium than the corresponding compounds from brain tissue of Tay-Sachs' disease. Evidence is presented that the higher tendency of gangliosides from brain tissue of Tay-Sachs' disease to be partitioned to the non polar medium is due to the lower sialic acid content of these compounds as compared with those isolated from nonpathological human brain.