Journal of the American Society for Mass Spectrometry

, Volume 19, Issue 12, pp 1799–1807

Dissociation of the N-Cα bond and competitive formation of the [zn−H]•+ and [cn+2H]+ product ions in radical peptide ions containing tyrosine and tryptophan: The influence of proton affinities on product formation

  • Chi-Kit Siu
  • Yuyong Ke
  • Galina Orlova
  • Alan C. Hopkinson
  • K. W. Michael Siu
Focus: Peptide Fragmentation

DOI: 10.1016/j.jasms.2008.09.026

Cite this article as:
Siu, CK., Ke, Y., Orlova, G. et al. J Am Soc Mass Spectrom (2008) 19: 1799. doi:10.1016/j.jasms.2008.09.026

Abstract

Dissociations at the N-Cα bond of tryptophan and tyrosine residues are the prevalent pathways in the fragmentations of radical cations of tripeptides that contain such as residues. This process involves a proton transfer from the β-carbon of the tryptophan or tyrosine residue to the carbonyl oxygen of the amide group, followed by cleavage of the N-Cα bond, generating low-lying proton-bound dimers that dissociate to give each an ionic and a neutral product. Formation of the [zn−H]∢+ or [cn+2H]+ ion is a competition between the two incipient fragments for the proton in a dissociating proton-bound dimer.

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Copyright information

© American Society for Mass Spectrometry 2008

Authors and Affiliations

  • Chi-Kit Siu
    • 1
  • Yuyong Ke
    • 1
  • Galina Orlova
    • 1
  • Alan C. Hopkinson
    • 1
  • K. W. Michael Siu
    • 1
  1. 1.Department of Chemistry and Centre for Research in Mass SpectrometryYork UniversityTorontoCanada
  2. 2.Department of ChemistrySt. Francis Xavier UniversityAntigonishCanada

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