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Composition and Structure Analysis of Gangliosides from Adult and Fetal Human Brain Precentral and Postcentral Gyrus Combining Mass Spectrometry and Thin-Layer Chromatography

Glycosphingolipids, constituents of external leaflet of plasma membrane, participate in vital processes of eukaryotic cells. Gangliosides (GG) are complex glycosphingolipids with sialylated oligosaccharide chains attached to a ceramide. Their highest content and pattern complexity are present in mammalian brain tissues. Specific changes in their expression occur during brain development, maturation, aging, and due to diseases. Here, we represent data of compositional and structural analysis of native GG mixtures and fractions of two functionally defined regions of human brain: the precentral and the postcentral gyrus of adult brain (17, 19, 54 years) and neocortical regions corresponding to prospective precentral and postcentral gyrus of fetal brain (24 g.w.). Dissected tissue samples were homogenized and total gangliosides were extracted and purified as native mixtures for analyses. HPTLC was used for separation of GG patterns and for preparative isolation of separated fractions for subsequent MS analysis. The MS screening and sequencing analyses were performed on a High Capacity Ion Trap Ultra mass spectrometer coupled, via mounting system, with a NanoMate robot incorporating ESI 400 Chip technology. Tandem MS was carried out by collision-induced dissociation. The HPTLC ganglioside patterns of all analyzed adult and fetal brain regions were basically similar, resembling the reference pattern of frontal cerebral cortex. Differences in total ganglioside concentrations as well as different relative abundances of some fractions were found between fetal and adult brain regions. Differences in relative abundances of individual species in precental vs. postcental gyrus were observed in both fetal and adult human brain. Comparative MS screening of the analyzed native mixtures revealed highly complex ganglioside compositions. Sequencing data allowing structural elucidation of some characteristic species will be presented.

gangliosides analysis; human brain regions; mass spectrometry; thin-layer chromatography

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