Protein glycosylation is ubiquitous and crucial for regulating biological processes in organisms. Given the heterogeneity and low abundance of glycoproteins, efficient and specific enrichment procedures are required for the mass spectrometry analysis of glycopeptides. Hydrophilic interaction liquid chromatography (HILIC) has emerged as an effective strategy for glycopeptide enrichment. However, the relatively weak hydrophilic affinity restricts the achievement of a satisfactory enrichment performance. Here, we presented a rational design of an amide and multihydroxyl complementary tailored metal-organic framework, denoted as U6N/Pv@Glc, which exhibited ultrahydrophilicity and enhanced glycan affinity. Our results demonstrated a significant increase in glycopeptide coverage after enrichment, accompanied by extremely low detection limits (0.05 fmol μL-1) and high selectivity (IgG/BSA, 1:4000) as evaluated using trypsin-digested standard glycoproteins. A total of 379 glycopeptides and 247 intact glycopeptides (containing a total of 1577 site-specific N-glycans) were identified and characterized within human serum samples from individuals with type 2 diabetes in-depth. Additionally, we extended the application of this material to capture undigested glycoproteins, demonstrating potential compatibility with top-down MS analysis. These results highlight the promising potential of this novel material for comprehensive glycoproteomic analysis of every potential aspect.
Keywords: enrichment; glycopeptides; glycoproteins; hydrophilic interaction chromatography; metal−organic frameworks; type 2 diabetes.