Specific enrichment of glycoproteins with polymer monolith functionalized with glycocluster grafted β-cyclodextrin

The low abundance of glycoproteins in complex samples results in the prerequisite role of efficient and selective enrichment of them. In the present work, we designed a new kind of glycosylation poly(hydroxyethyl methacrylate-pentaerythritol triacrylate) monolith functionalized with glycocluster grafted β -cyclodextrin for the enrichment of glycoproteins. The introduced modifiers endowed the monolithic material with enhanced hydrophilicity and surface area, which benefitted to improve the enrichment selectivity and extraction efficiency for glycopeptides. By combining with MALDI-MS detections, 22 glycopeptides from horseradish peroxidase digest were captured with the developed monolith while 4 glycopeptides were enriched by commercially available agarose matrix column. LOD of 6.6   pmol was attained. When applied to the enrichment of glycopeptides from complex protein samples and human lymphoma (U937) cell line, the prepared monolith exhibited high selectivity for glycopeptides.