Neutral fragment mass spectra via ambient thermal dissociation of peptide and protein ions

Hao Chen, Livia S. Eberlin, R. Graham Cooks

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


A novel method for the fragmentation of peptide and protein ions at atmospheric pressure outside the mass spectrometer is described. Peptide/protein ions generated by electrosonic spray ionization (ESSI) are carried through a heated coiled metal tube where they fragment. Fragment ions of types a, b, and y are observed for peptides such as angiotensin II and bradykinin. In the case of phosphopeptides, informative b and y ions which preserve the labile phosphate groups are observed in the negative ion mode, which is potentially useful in the location of phosphorylation sites in proteins through chemical analysis of phosphopeptides. The thermal dissociation method extends to proteins such as ubiquitin and myoglobin, giving rise to y-type and other fragment ions. The most important feature of this method is that it also allows characterization of the neutral fragments arising from thermal dissociation by use of on-line corona discharge ionization. This neutral re-ionization experiment is much easier to perform outside the mass spectrometer than as conventionally done, in vacuum. It yields increased structural information from the resulting mass spectra in both the positive and the negative ion modes.

Original languageEnglish (US)
Pages (from-to)5880-5886
Number of pages7
JournalJournal of the American Chemical Society
Issue number18
StatePublished - May 9 2007
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry


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