Research groups led by Prof. QING Guangyan and Prof. LIANG Xinmiao from the
Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences proposed a brand-new dynamic covalent chemical method of Schiff base hydrolysis to precisely capture sialylated glycans. The results were published in
J. Am. Chem. Soc.The sialylated glycans distribute widely on the cell surface as if a layer of "glycocalyx". It plays a vital role in many physiological processes, such as viral infection, immune activation, cancer occurrence, development and migration.
Sialylated glycoproteins have been widely used as clinical biomarkers for various cancers. However, identification and analysis of the sialylated glycans is complex and challenging.
A new and highly efficient material system is needed to overcome the problems of sialylated glycan enrichment and separation in complex bio-samples and promote the comprehensive development of glycoproteomics.
Based on a strategy of dynamic covalent chemistry, the researchers accurately captured sialylated glycans. Different from the traditional static affinity strategy, this new strategy cleverly uses the dynamic covalent chemical bonds present in Schiff base, forming a stable complex between its hydrolyzed part and the sialylated glycan.
The developed material exhibits excellent enrichment selectivity for the sialylated glycopeptides, high adsorption capacity and satisfactory enrichment recovery rate, reaching a high level in the field of glycopeptide enrichment.
This provides biochemists with a novel strategy that can be used to accurately capture glycan information, which is closely related to the occurrence of cancer and immune diseases.
More importantly, the researchers disclosed an interesting story hidden behind the Schiff base hydrolysis reaction, one hydrolysis product forms a stable complex with the sialylated glycan, while the other product occurs ordered self-assembly in solution, both of which remarkably promote the hydrolysis reaction.
This study shows the unique advantages of dynamic covalent chemistry in the fields of glycoproteomics and biomolecular sensing. It was supported by the National Natural Science Foundation of China, DICP Innovation Funding and Liaoning Revitalization Talents Program.
Significance of sialylated glycan and the enrichment concept (Image by XIONG Yuting)
