Membrane glycomics reveal heterogeneity and quantitative distribution of cell surface sialylation. Issue 29 (5th July 2018)

• Record Type: Journal Article
• Authors: Park, Diane Dayoung; Xu, Gege; Wong, Maurice; Phoomak, Chatchai; Liu, Mingqi; Haigh, Nathan E.; Wongkham, Sopit; Yang, Pengyuan; Maverakis, Emanual; Lebrilla, Carlito B.
• Is Part Of: Chemical science. Volume 9:Issue 29(2018)
• Page Start: 6271
• Page End: 6285
• Publication Date: 2018-07-05
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8sc01875h
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Sialic acid distribution was quantified by LC-MS/MS. The number of sialylated glycoforms increases at sites nearest to the transmembrane domain. Abstract : Given that unnatural sugar expression is metabolically achieved, the kinetics and disposition of incorporation can lend insight into the temporal and localization preferences of sialylation across the cell surface. However, common detection schemes lack the ability to detail the molecular diversity and distribution of target moieties. Here we employed a mass spectrometric approach to trace the placement of azido sialic acids on membrane glycoconjugates, which revealed substantial variations in incorporation efficiencies between N -/ O -glycans, glycosites, and glycosphingolipids. To further explore the propensity for sialylation, we subsequently mapped the native glycome of model epithelial cell surfaces and illustrate that while glycosylation sites span broadly across the extracellular region, a higher number of heterogeneous glycoforms occur on sialylated sites closest to the transmembrane domain. Beyond imaging techniques, this integrative approach provides unprecedented details about the frequency and structure-specific distribution of cell surface sialylation, a critical feature that regulates cellular interactions and homeostatic pathways.