Cyclic Ion Mobility Mass Spectrometry Distinguishes Anomers and Open-Ring Forms of Pentasaccharides

Abstract

There is increasing biopharmaceutical  interest in oligosaccharides and glycosylation. A key requirement for these sample types is the ability to characterize the chain length, branching, type of monomers, and importantly stereochemistry and anomeric configuration. Herein, we showcase the multi-function capability of a cyclic ion mobility (cIM) separator embedded in a quadrupole/time-of-flight mass spectrometer (Q-ToF-MS). The instrument design enables selective activation of mobility-separated precursors followed by cIM separation of product ions, an approach analogous to MSn. Using high cIM resolution, we demonstrate the separation of three isomeric pentasaccharides and, moreover, that three components are present for each compound. We show that structural differences between product ions reflect the precursor differences in some cases but not others. These findings are corroborated by a heavy oxygen labelling approach. Using this methodology, the identity of fragment ions may be assigned. This enables us to postulate that the two main components observed for each pentasaccharide are anomeric forms. The remaining low abundance component is assigned as an open-ring form.

J. Am. Soc. Mass Spectrom. 2019 April 11. doi: 10.1007/s13361-019-02168-9. [Epub ahead of print]
Jakub Ujma, David Ropartz, Kevin Giles, Keith Richardson, David Langridge, Jason Wildgoose, Martin Green, Steven Pringle
Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
INRA, UR1268 Biopolymers Interactions Assemblies, Rue de la Géraudière, B.P. 71627F-44316, Nantes, France
 

DOI: 10.1007/s13361-019-02168-9