LAUSR

Ganglioside is an important class of lipid species involving in intercellular signaling and various diseases, especially for neurodegenerative diseases. Systematic ganglioside profiling is challenging due to their naturally low abundance and highly diverse species. Herein, a new data independent acquisition and parallel reaction monitoring (DIA/PRM) method with superior sensitivity was developed. The untargeted DIA acquisition consecutively records all the precursor ion and fragment ions at the same time, while the targeted PRM analysis with versatile higher collisional dissociation generates full MS/MS spectra for structure elucidation and verification. As compared with traditional data dependent acquisition (DDA), the DIA/PRM method unbiasedly detected majority of abundant ganglioside species and as low as 50 pg ganglioside in the untargeted manner. Gangliosides in four kinds of biological samples including the mouse brain, mouse plasma, Hela cell and human colon cancer tissue were systematically identified, and low abundant ganglioside species were further extended based on linear chromatography retention rules of the most frequently detected ganglioside species. A total of 383 ganglioside features were defined with 329 of them derived from 32 ganglioside species. Taking advantage of the high-resolution MS analysis, rare ganglioside species were further elucidated according to their characteristic fragment ions and neutral losses. In total, 18 gangliosides with ceramide carbon number from 20 to 25 and modified gangliosides, including 18 acetylated, 8 di-acetylated, 1 phosphorylated, 36 N-glycolyneuraminic acid (NeuGc)-containing and 7 di-NeuGc-containing gangliosides, were newly identified. The developed DIA/PRM method therefore generated a rich ganglioside resource for further functional exploration and is an unique alternative of DDA analysis for global ganglioside profiling in various biological systems.