Cell surface glycoprotein complexes regulate critical biological processes such as intercellular recognition， signal transduction， and immune modulation through dynamic glycosylation modifications. Their spatiotemporally specific in vivo interaction networks directly influence disease pathogenesis and therapeutic responses. However， studying these interactions faces substantial technical challenges due to the weak/transient nature of glycoprotein interactions and the complexity of glycosylation modifications. In this study， we employed membrane-impermeable crosslinkers combined with oxidized glycan-hydrazide specific reactions and in vivo chemical crosslinking-mass spectrometry technology， successfully achieving high-selectivity capture of glycoprotein interactions on living cell surfaces. This approach identified 4 457 high-confidence glycosylation sites corresponding to 1 637 glycoproteins in HeLa cells， with 84% localized to the cell surface. Further analysis revealed that over 90% of the identified protein-protein interaction networks comprised glycoprotein-glycoprotein interactions， glycoprotein-associated protein interactions， and associated protein interaction networks. Key glycoprotein-mediated interactions， such as those involving integrin beta-1（ITGB1）， were elucidated. This methodology provides crucial insights for deciphering glycan functionality in cell surface glycoprotein interactions， contributes to revealing the pivotal role of glycosylation in biological processes like cellular signaling and immune regulation， and offers novel strategies for early disease diagnosis and precision therapeutics
Liu et al. (Fri,) studied this question.