Fragmentation of singly protonated peptides via a combination of infrared and collisional activation

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


The coupling of matrix-assisted laser desorption/ionization (MALDI) to Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) provides an exceptionally capable platform for peptide analysis, but an important limitation of this approach is the difficulty in obtaining informative tandem mass spectra (MS/MS) of singly protonated peptides. This difficulty is especially pronounced with peptide ions containing basic amino acid residues (for example, tryptic peptides). While such ions can be fragmented in some instrument configurations, most FTICR instruments have comparatively little facility for high-energy fragmentation. Here, a novel MS/MS approach implemented with MALDI-FTICR-MS and specifically intended for enhanced fragmentation of singly protonated peptides is described. The method involves infrared irradiation in concert with the simultaneous application of sustained off-resonance irradiation collision-induced dissociation (SORI-CID). This form of MS/ MS, described as a combination of infrared and collisional activation (CIRCA), is shown to provide a greater capacity for dissociation of singly charged model peptide ions as compared to infrared multiphoton dissociation (IRMPD) or SORI-CID alone. Overall, the CIRCA approach is demonstrated to be a feasible technique for accessing useful fragmentation pathways of singly charged peptides, including those harboring basic amino acid residues-a crucial feature in the context of proteomics.

Original languageEnglish (US)
Pages (from-to)8506-8511
Number of pages6
JournalAnalytical Chemistry
Issue number24
StatePublished - Dec 15 2006

ASJC Scopus subject areas

  • Analytical Chemistry


Dive into the research topics of 'Fragmentation of singly protonated peptides via a combination of infrared and collisional activation'. Together they form a unique fingerprint.

Cite this