Size-selective enrichment of N-linked glycans using highly ordered mesoporous carbon material and detection by MALDI-TOF MS.

Many diseases are characterized by the changes of either glycan structure or glycosylation site of glycoproteins. The glycan profiling can provide the overview of glycosylation in despite of the absence of the glycosylation sites, which in turn simplifies the complexity of disease diagnosis. Herein, we describe a simple method to profile the N-linked glycans by MALDI-TOF MS with the enrichment using oxidized ordered mesoporous carbon, taking advantages of the size-exclusive effect of mesopore against proteins as well as the interaction between glycans and carbon. Twenty four N-linked glycans derived from ovalbumin could be efficiently detected with high signal-to-noise (S/N) ratios and sufficient peak intensities. In the analysis of complex serum samples, 32 N-linked glycans could be profiled, and 5 (4 core-fucosylated glycans) of them were distinguished from liver cancer and healthy samples.