Advances in mass spectrometry‐based glycomics—An update covering the period 2017–2021

Abstract

The wide variety of chemical properties and biological functions found in proteins is attained via post‐translational modifications like glycosylation. Covalently bonded to proteins, glycans play a critical role in cell activity. Complex structures with microheterogeneity, the glycan structures that are associated with proteins are difficult to analyze comprehensively. Recent advances in sample preparation methods, separation techniques, and MS have facilitated the quantitation and structural elucidation of glycans. This review focuses on highlighting advances in MS‐based techniques for glycomic analysis that occurred over the last 5 years (2017–2021) as an update to the previous review on the subject. The topics of discussion will include progress in glycomic workflow such as glycan release, purification, derivatization, and separation as well as the topics of ionization, tandem MS, and separation techniques that can be coupled with MS. Additionally, bioinformatics tools used for the analysis of glycans will be described.

Liquid chromatography and capillary electrophoresis in glycomic and glycoproteomic analysis

“…Although PGC is also a powerful stationary phase material for separation of glycopeptide isomers, it has worse robustness and reproducibility of resolution and retention time comparing with the separation on HILIC columns [ 83 ]. A chip-based PGC column (0.075 × 150 mm; 5.0 µm) was used for the separation of pronase digested N - and O -linked glycopeptides of RNase B, human IgG, bovine lactoferrin, and bovine κ-casein by Hua et al [ 84 ].…”

The known unknowns of apolipoprotein glycosylation in health and disease

“…Importantly, although liquid chromatography or capillary electrophoresis-based separation followed by MS analysis is applicable to glycan structure elucidation and quantification, structural elucidation of novel glycans requires validation by exoglycosidase or endoglycosidase digestion. A detailed overview of advances in glycomic strategies is summarized in recent reviews ( Dong et al., 2018 ; Donohoo et al., 2022 )…”

“…A detailed overview of advances in glycomic strategies is summarized in recent reviews (Dong et al, 2018;Donohoo et al, 2022) Determining the glycan compositions present at specific amino acid residues is key to identifying apolipoprotein glycoforms (Oliveira et al, 2021). There are two glycoproteomic approaches currently applied to study apolipoprotein glycoforms -namely protein-level and peptide-level analyses.…”

Analysis of Viral Spike Protein N-Glycosylation Using Ultraviolet Photodissociation Mass Spectrometry

“…20,21 Extensive optimization and comparison of CAD and ETD methods for glycopeptides suggest that CAD methods outperform ETD approaches for N-linked glycoproteomics. 17 Despite the advances in enrichment techniques, 22−24 MS/ MS strategies, 9,25,26 and search engines 27,28 for glycoproteomics, the need for methods that perform well for proteins containing heterogeneous mixtures of glycans (such as viral proteins) and for profiling glycoproteins in complex mixtures and for unraveling intersaccharide linkages remains unmet. 29 As such, key aims in the quest to map glycosylation are to characterize the peptide sequence, localize the sites of modifications, and determine both glycan composition and intersaccharide linkages.…”