Combining Glycosidases and Nanopore Technology for Glycan Sequencing

The efficient characterization of glycan structures remains a critical challenge. Direct glycan sequencing technologies with improved sensitivity and throughput are still needed. Here, we propose a glycan sequencing strategy based on glycosidase -assisted nanopore sensing. We used engineered nanopore -hemolysin (M113R/T115A), which provided high-resolution discrimination of monosaccharide volume differences and sensitivity to variations in glycan chain length. By utilizing the specificity of glycosidases, we sequentially hydrolyzed the terminal residues of the glycan chains and detected the characteristic shifts in electrical signals generated by the translocation of hydrolysis products. The accuracy of recognition of hydrolysis fragments achieved over 90 % using machine learning. This allowed us to efficiently and conveniently determine the sequence of consecutive monosaccharide units in the glycan chains. Based on this principle, we conducted a proof-of-concept demonstration on actual samples and verified the accuracy via HPLC-MS. We achieved the sequencing of consecutive units in glycan chains, confirming the theoretical feasibility of glycosidase -assisted nanopore glycan sequencing. With future optimization, the development of arrayed nanopore glycan sequencing technology based on hydrolysis strategy will provide an innovative approach for rapid decoding of glycans, which could promote the progress of glycomics research and glycobiology.