How General Is Anomeric Retention during Collision-Induced Dissociation of Glycans?

: Despite the essential role that glycans play in many biological processes, their isomeric com-plexity makes their structural determination partic-ularly challenging. Tandem mass spectrometry has played a central role in glycan analysis, and recent work has shown that fragments generated by colli-sion-induced dissociation (CID) of disaccharides can retain the anomeric configuration of the glyco-sidic bond. If this result proves to be general, it would provide a powerful new tool for glycan se-quencing. In this work, we use messenger-tagging infrared (IR) spectroscopy to investigate the gener-ality of anomer retention in CID by exploring dif-ferent fragmentation channels in glycans of in-creasing complexity. Our results demonstrate that anomericity seems to be retained irrespective of fragment size and branching.