Journal of the American Society for Mass Spectrometry

, Volume 19, Issue 11, pp 1706–1715

Resolving and assigning N-linked glycan structural isomers from ovalbumin by IMS-MS


  • Manolo D. Plasencia
    • Department of ChemistryIndiana University
  • Dragan Isailovic
    • Department of ChemistryIndiana University
  • Samuel I. Merenbloom
    • Department of ChemistryIndiana University
  • Yehia Mechref
    • Department of ChemistryIndiana University
    • Department of ChemistryIndiana University

DOI: 10.1016/j.jasms.2008.07.020

Cite this article as:
Plasencia, M.D., Isailovic, D., Merenbloom, S.I. et al. J Am Soc Mass Spectrom (2008) 19: 1706. doi:10.1016/j.jasms.2008.07.020


Ion mobility-mass spectrometry (IMS-MS) and molecular modeling techniques have been used to characterize ovalbumin N-linked glycans. Some glycans from this glycoprotein exist as multiple isomeric forms. The gas-phase separation makes it possible to resolve some isomers before MS analysis. Comparisons of experimental cross sections for selected glycan isomers with values that are calculated for iterative structures generated by molecular modeling techniques allow the assignment of sharp features to specific isomers. We focus here on an example glycan set, each having a m/z value of 1046.52 with formula [H5N4+2Na]2+, where H corresponds to a hexose, and N to a N-acetylglucosamine. This glycan appears to exist as three different isomeric forms that are assignable based on comparisons of measured and calculated cross sections. We estimate the relative ratios of the abundances of the three isomers to be in the range of ∼1.0:1.35:0.85 to ∼1.0:1.5:0.80. In total, IMS-MS analysis of ovalbumin N-linked glycans provides evidence for 19 different glycan structures corresponding to high-mannose and hybrid type carbohydrates with a total of 42 distinct features related to isomers and/or conformers.

Download to read the full article text

Copyright information

© American Society for Mass Spectrometry 2008