StrucGP: de novo structural sequencing of site-specific N-glycan on glycoproteins using a modularization strategy

• DOI: 10.1038/s41592-021-01209-0
• Publication Date: 2021-08-02T16:03:47Z
• Authors: Jiechen Shen; Li Jia; Liuyi Dang; Yuanjie Su; Jie Zhang; Yintai Xu; Bojing Zhu; Zexuan Chen; Jingyu Wu; Rongxia Lan; Zhifang Hao; Chen Ma; Ting Zhao; Ni Gao; Jieyun Bai; Yuan Zhi; Jun Li; Junying Zhang; Shisheng Sun
• Keywords: Male; Mice, Inbred C57BL; Mice; 0303 health sciences; 03 medical and health sciences; Glycosylation; Polysaccharides; Glycopeptides; Animals; Algorithms; Glycoproteins

Precision mapping of glycans at structural and site-specific level is still one of the most challenging tasks in the glycobiology field. Here, we describe a modularization strategy for de novo interpretation of N-glycan structures on intact glycopeptides using tandem mass spectrometry. An algorithm named StrucGP is also developed to automate the interpretation process for large-scale analysis. By dividing an N-glycan into three modules and identifying each module using distinct patterns of Y ions or a combination of distinguishable B/Y ions, the method enables determination of detailed glycan structures on thousands of glycosites in mouse brain, which comprise four types of core structure and 17 branch structures with three glycan subtypes. Owing to the database-independent glycan mapping strategy, StrucGP also facilitates the identification of rare/new glycan structures. The approach will be greatly beneficial for in-depth structural and functional study of glycoproteins in the biomedical research.