Dissociation reactions of gaseous ferro-, ferri-, and apo-cytochrome c ions

  • J. Mitchell Wells
  • Gavin E. Reid
  • Brian J. Engel
  • Peng Pan
  • Scott A. McLuckey
Short Communication


Electrochemical reduction of the iron bound in the heme group of cytochrome c is shown to occur in the nano-electrospray capillary if the protein is sprayed from neutral water using a steel wire as the electrical contact. Quadrupole ion trap collisional activation is used to study the dissociation reactions of cytochrome c as a function of the oxidation state of the iron. Oxidized (Fe(III)) cytochrome c dissociates via sequence-specific amide bond cleavage, while the reduced (Fe(II)) form of the protein dissociates almost exclusively by loss of protonated heme. Apo-cytochrome c, from which the heme has been removed either via gas-phase dissociation of the reduced holo-protein or via solution chemistry, dissociates via amide bond cleavage in similar fashion to the oxidized holo-protein.


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Copyright information

© American Society for Mass Spectrometry 2001

Authors and Affiliations

  • J. Mitchell Wells
    • 1
  • Gavin E. Reid
    • 1
  • Brian J. Engel
    • 1
  • Peng Pan
    • 1
  • Scott A. McLuckey
    • 1
  1. 1.Department of ChemistryPurdue UniversityWest LafayetteUSA

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