A New titania glyco-purification tip for the fast enrichment and efficient analysis of glycopeptides and glycans by MALDI-TOF-MS

Enrichment and/or purification of intact glycopeptides and derivatized glycans are essential for mass spectrometry-based glycoproteomics and glycomics because of analytical challenges observed in the analysis. Here, a titania-based material was synthesized using a facile sol-gel method for the efficient analysis of glycopeptides and glycans. The glycopeptide enrichment efficacy of the titania-based sol-gel material was evaluated by the enrichment of IgG N-glycopeptides from their proteolytic products. The selectivity and sensitivity (0.5 fmol μL⁻¹) of the titania-based sol-gel material was found to be quite high when compared with commercial TiO₂. A pipette-tip application for rapid glycoproteomic and glycomic analysis was developed by packing titania-based material into the pipette tips. The released and derivatized N-glycans of human plasma, IgG and human transferrin were successfully purified by titania glyco-purification tips for the analysis by MALDI-MS. The enrichment performance of the titania glyco-purification tip was tested using human plasma digest as a real-world complex sample and, 112 N-glycopeptides from human plasma glycoproteins were detected by the analysis of enriched samples by nLC-QTOF-MS/MS. Finally, the structural characterization of the material was achieved in detail using various characterization approaches.