Discrimination of Isomeric Glycans via High-sensitive Engineered Nanopore

ABSTRACT Glycan isomers are the basis for forming the spatial structure of glycans, which poses great challenges to glycan structural analysis and hinders the study of the relationship between structure and function. An economical and convenient analytical method with high resolution is still in demand. Here, we designed an engineered α-hemolysin nanopore with double-mutants (α-HL M113R/T115A) to achieve sensing of glycans with different glycosidic linkages. By extracting three parameters to depict a 3D scatter plot, four glycans with different degrees of polymerization and glycosidic bonds could be distinguished. Through molecular dynamics (MD), we further elucidated the motion trajectories of two different glycosidic bonds in the pore region. In addition, the sensing ability was also applied in the direct identification of glycans in mixture systems. The obtained nanopore data permitted us to achieve a separation accuracy of over 90% independent of the assistance of machine learning algorithms. Designing biological nanopores with high discrimination and sensitivity for glycans with different lineages paves the way for nanopore glycan profiling and potentially sequencing.