Ion Mobility-Mass Spectrometry on Carbohydrates

Glycosylation is one of the most common and most diverse post-translational modifications occurring in proteins. The involved carbohydrates, the glycans, are responsible for a variety of biological functions including apoptosis, cell-cell-recognition and immune response and are therefore linked to various diseases. The intrinsic chemical complexity and often identical mass of carbohydrates makes their direct structural identification on basis of conventional tandem MS data challenging. To overcome these problems, we combine mass spectrometry with ion mobility (IM) spectrometry, which serves as an additional “gas-phase chromatography” step in which ions are not only separated according to their mass and charge, but also their size and shape. This allows the separation of regio- and stereoisomers and yields an additional structural parameter in form of the rotationally averaged collision cross section (CCS). Experiments are performed on a commercially available hybrid tandem IM-MS instrument (Synapt G2-S) in which the ions of interest can be fragmented prior or after IM separation.


Downloads

  • Excel spreadsheet to estimate CCSs from traveling wave ion mobility mass spectrometry data. See file for further details and literature.
  • pdf with step-by-step description of the instrument optimization and calibration procedure.

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