A lectin-based isolation/enrichment strategy for improved coverage of N-glycan analysis

Glycomics provides an increasingly useful research tool as the genomes and proteomes of more and more animal species are elucidated. In view of the general complexity and heterogeneity of glycans, improved depth-of-coverage and sensitivity are required for glycosylation analysis. In this study, we established the lectin-based isolation/enrichment strategy for total glycomic information. Specific lectins are added onto the filter to capture corresponding glycans prior to release of N-glycans by peptide N-glycosidase F (PNGase F). Non-bound glycans and bound glycans are released and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), respectively. Application of the strategy to chicken ovalbumin, normal mouse mammary epithelial cells (NMuMG), and human serum resulted in detection of 5, 6, and 11 additional N-glycan structures, respectively. The strategy facilitates identification of intact N-glycans in biological samples, and can be extended to detailed analysis of O-glycome or glycoproteome.