Strategies for Proteome-Wide Quantification of Glycosylation Macro-and Micro-Heterogeneity

Abstract

Protein glycosylation governs key physiological and pathological processes in human cells. Aberrant glycosylation is thus closely associated with disease progression. Mass spectrometry (MS)-based glycoproteomics has emerged as an indispensable tool for investigating glycosylation changes in biological samples with high sensitivity. Following rapid improvements in methodolo-gies for reliable intact glycopeptide identification, site-specific quantification of glycopeptide macro-and micro-heterogeneity at the proteome scale has become an urgent need for exploring glycosylation regulations. Here, we summarize recent advances in N-and O-linked glycoproteomic quantification strategies and discuss their limitations. We further describe a strategy to propagate MS data for multilayered glycopeptide quantification, enabling a more comprehensive examination of global and site-specific glycosylation changes. Altogether, we show how quantitative glycopro-teomics methods explore glycosylation regulation in human diseases and promote the discovery of biomarkers and therapeutic targets.