Journal of the American Society for Mass Spectrometry

, Volume 15, Issue 12, pp 1869–1873

Electron capture dissociation at low temperatures reveals selective dissociations

Authors

  • Romulus Mihalca
    • FOM Institute for Atomic and Molecular Physics (AMOLF)
  • Anne J. Kleinnijenhuis
    • FOM Institute for Atomic and Molecular Physics (AMOLF)
  • Liam A. McDonnell
    • FOM Institute for Atomic and Molecular Physics (AMOLF)
  • Albert J. R. Heck
    • Department of Biomolecular Mass Spectrometry, Bijvoet Center for Biomolecular Research, Utrecht Institute for Pharmaceutical SciencesUtrecht University
    • Department of Biomolecular Mass Spectrometry, Bijvoet Center for Biomolecular Research, Utrecht Institute for Pharmaceutical SciencesUtrecht University
    • FOM Institute for Atomic and Molecular Physics
Articles

DOI: 10.1016/j.jasms.2004.09.007

Cite this article as:
Mihalca, R., Kleinnijenhuis, A.J., McDonnell, L.A. et al. J Am Soc Mass Spectrom (2004) 15: 1869. doi:10.1016/j.jasms.2004.09.007

Abstract

Electron capture dissociation at 86 K of the linear peptide Substance P produced just two backbone fragments, whereas at room temperature eight backbone fragments were formed. Similarly, with the cyclic peptide gramicidin S, just one backbone fragment was formed at 86 K but five at room temperature. The observation that some backbone scissions are active and others inactive, when all involve N-Cα cleavages and have a high rate constant, indicates that the more specific fragments at low temperatures reflects the reduced conformation heterogeneity at low temperatures. This is supported by reduced or inactive hydrogen loss, a channel that has previously been shown to be affected by conformation. The conclusion that the ECD fragments are a snapshot of the conformational (intramolecular solvation shell) heterogeneity helps explain how the relative intensities of ECD fragments can be different on different instrument and highlights the common theme in methodologies used to increase sequence coverage, namely an increase in the conformational heterogeneity of the precursor ion population.

Copyright information

© American Society for Mass Spectrometry 2004