Modulation of Core-Fucosylation Oxidation for Selective Enrichment and Characterization of Cell Surface Glycoprotein.

Protein core-fucosylation plays a crucial role in regulating cell surface protein functions and is involved in various biological processes, including cell signaling, immune response, and cancer progression. However, core-fucosylation (CF) poses particular challenges in identification and characterization due to its low abundance and the high heterogeneity of N-glycosylation. To overcome these challenges, this study systematically investigated the oxidation mechanisms of core-fucose and developed a selective enrichment strategy that combines chemical oxidation with glycan truncation for cell surface core-fucosylation characterization. Specifically, sodium periodate was employed to selectively oxidize cell surface glycans. In combination with the endoglycosidases Endo M and Endo F3, which possessed complementary substrate specificity and broad tolerance, this approach efficiently truncated N-glycans, leaving core-fucosylated glycopeptides bearing aldehyde tags. Utilizing reversible hydrazide chemistry, core-fucosylated glycopeptides were selectively enriched. The developed strategy was applied to profile cell surface core-fucosylated protein in HeLa cells, which yielded 74 core-fucosylated glycopeptides corresponding to 21 key cell surface drug targets, thereby validating the efficacy of this approach. Collectively, this study systematically investigated the mechanism of core-fucosylation oxidation and developed a new technical tool for studying cell surface protein core-fucosylation.