Core-shell structured magnetic metal-organic framework composites for highly selective detection of N-glycopeptides based on boronic acid affinity chromatography

Boronic acid affinity chromatography (BAAC) is one of the most significant methods in glycoproteomics research due to its low bias towards glycopeptides and easy enrichment process. In this work, core-shell structured magnetic metal-organic framework (MOF) composites with abundant boronic acid groups were designed and synthesized for selective glycopeptide enrichment based on BAAC. The as-prepared core-shell structured magnetic MOF composites (denoted as Fe3O4@PVP/PEI@MOF (B)) inherited strong magnetic responsiveness from the Fe3O4 core as well as ultrahigh surface area and abundant boronic acid sites from the MOF shell. The affinity between boronic acid and cis-diols groups endowed the composites with improved sensitivity (0.5 fmol/μL) and selectivity (1:100) towards glycopeptides, achieving remarkable results in glycopeptides detection from standard glycoprotein digests as well as complex bio-samples. As a result, a total of 209 N-glycosylation peptides from 89 different glycoproteins were identified from human serum digests, indicating its broad prospect in glycoproteome study.