Characterization of a novel brain neutral glycosphingolipid composition in house musk shrew (Suncus murinus)

Abstract

Glycosphingolipids were extracted from the brain of house musk shrew (Suncus murinus). Neutral glycosphingolipids were purified by QAE-Sephadex column chromatography followed by high-performance liquid chromatography using an Iatrobeads column. Purified glycosphingolipids were identified by high-performance thin-layer chromatography, carbohydrate analysis, fast-atom bombardment mass spectrometry and TLC immunostaining. The ganglioside pattern was almost the same as the pattern obtained for rat brain gangliosides. The brain of S. murinus, however, was unique in its neutral glycosphingolipid composition; it contained gangliotriaosylceramide and gangliotetraosylceramide as the major neutral glycosphingolipids in addition to monohexosylceramides. Mass spectroscopy analysis showed that C18:1 sphingosine and C24:0 normal fatty acids were the major ceramide constituents in the glycosphingolipis, except in the case where a slower-migrating monohexosylceramide that contained C24 h:0 hydroxy fatty acids was observed. A day after birth, monohexosylceramide contained only normal fatty acids. The amounts of hydroxy-fatty-acid-containing monohexosylceramide increased rapidly as the age of the animals increased, and the ratio of these two kinds of monohexosylceramides was reversed within five weeks. Monohexosylceramide, ganglioside, and sulfatide contents in bulbus olfactorius were almost equal in amount in contrast to the glycolipids in the cerebrum and cerebellum that contained monohexosylceramide as the major constituent. The amount of monohexosylceramide in the bulbus olfactorius was 0.3-0.4 times the values obtained for the cerebrum and cerebellum.