Differentiation of aspartic and isoaspartic acids using electron transfer dissociation

  • Peter B. O’ConnorEmail author
  • Jason J. Cournoyer
  • Sharon J. Pitteri
  • Paul A. Chrisman
  • Scott A. McLuckey
Short Communication


Electron-transfer dissociation allows differentiation of isoaspartic acid and aspartic acid residues using the same c + 57 and z − 57 peaks that were previously observed with electron capture dissociation. These peaks clearly define both the presence and the position of isoaspartic acid residues and they are relatively abundant. The lower resolution of the ion trap instrument makes detection of the aspartic acid residue’s diagnostic peak difficult because of interference with side-chain fragment ions from arginine residues, but the aspartic acid residues are still clearly observed in the backbone cleavages and can be inferred from the absence of the isoaspartic acid diagnostic ions.


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Copyright information

© American Society for Mass Spectrometry 2005

Authors and Affiliations

  • Peter B. O’Connor
    • 1
    Email author
  • Jason J. Cournoyer
    • 1
  • Sharon J. Pitteri
    • 2
  • Paul A. Chrisman
    • 2
  • Scott A. McLuckey
    • 2
  1. 1.Mass Spectrometry Resource, Department of BiochemistryBoston University School of MedicineBostonUSA
  2. 2.Department of ChemistryPurdue UniversityWest LafayetteUSA

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