Advances in Fragmentation Techniques for Glycomics and Glycoproteomics

Glycosylation, the enzymatic addition of carbohydrate moieties to proteins, is essential for immune recognition, protein folding, and disease progression. The structural complexity of glycans and the heterogeneity of glycosylation sites present significant challenges towards accurate identification and quantification, necessitating advanced methodologies for comprehensive characterization. Tandem MS (MS/MS) has emerged as the primary analytical platform for glycomics and glycoproteomics. This review highlights the recent developments in fragmentation techniques, ranging from well-established techniques such as CID/HCD and ETD, to newer and more advanced techniques such as electron-based methods (EThcD), photodissociation strategies (UVPD, IRMPD), and hybrid approaches (sceHCD, EThcD-sceHCD, HCD-pd-ETD), each providing distinct advantages towards glycan structure elucidation and glycosite mapping. This review also discusses emerging computational strategies, especially deep learning for automated interpretation of complex glycomics and glycoproteomics data.