4. Identification of the accumulated ganglioside

Abstract

Publisher Summary This chapter presents the researcher's own experience in identifying the accumulated ganglioside. His work on isolating ganglioside from human brains, including a Tay-Sachs brain was initially hampered by the low yields of ganglioside with the available ganglioside determination method, and by the lack of a pure sialic acid standard. Folch et al., in 1951 reported the isolation of a new high-molecular weight component of brain, which he named strandin. Folch et al.'s study was also important because the group developed a new procedure, a solvent partition method, for the isolation of ganglioside, which markedly increased the recovery of a purer ganglioside fraction than that obtained using Klenk's procedure. When gangliosides from Tay-Sachs brains were isolated with the same methods as used for the gangliosides from normal human brain, the trisaccharide of normal and Tay-Sachs brain showed identical compositions, the same yields at stepwise degradation, and the same permethylated sugars. It was therefore suggested that the Tay-Sachs ganglioside had the same structure as the normal major monosialoganglioside, except that it lacked the terminal galactose. The Tay-Sachs brain also showed a large accumulation of the neutral ceramide gangliotriaose, also known as asialo Tay-Sachs ganglioside. It was also demonstrated that the Tay-Sachs ganglioside occurred in brains of infants as well as in aged persons and was thus a normal brain ganglioside component.