NRC Publication Number 2005-42553
Targeted comparative proteomics by liquid chromatography/matrix-assisted laser desorption/ionization triple-quadrupole mass spectrometry†
Article first published online: 8 FEB 2006
Copyright © 2006 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 20, Issue 5, pages 904–910, 15 March 2006
How to Cite
Melanson, J. E., Chisholm, K. A. and Pinto, D. M. (2006), Targeted comparative proteomics by liquid chromatography/matrix-assisted laser desorption/ionization triple-quadrupole mass spectrometry. Rapid Commun. Mass Spectrom., 20: 904–910. doi: 10.1002/rcm.2391
- Issue published online: 8 FEB 2006
- Article first published online: 8 FEB 2006
- Manuscript Accepted: 27 OCT 2005
- Manuscript Revised: 30 SEP 2005
- Manuscript Received: 28 JUL 2005
- MDS-SCIEX and the NRC Genomics and Health Initiative
Here we report the first application of a matrix-assisted laser desorption/ionization (MALDI) triple-quadrupole mass spectrometer for targeted proteomics. Employing an amine-specific isotopic labelling approach, the technique was validated using five randomly selected bovine serum albumin peptides differentially labelled at known ratios. An indirect benefit of the isotopic labelling technique is a significant enhancement of the a1 ion in tandem mass (MS/MS) spectra of all peptides studied. Therefore, the a1 ion was selected as the fragment ion for multiple reaction monitoring (MRM) in all cases, eliminating tedious method development and optimization. Accurate quantification was achieved with an average relative standard deviation (RSD) of 5% (n = 5) and a detection limit of 14 amol. The technique was then applied to validate an important virulence biomarker of the fungal pathogen Candida albicans, which was not accurately quantified using global proteomics experiment employing two-dimensional liquid chromatography/electrospray ionization tandem mass spectrometry (2D-LC/ESI)-MS/MS. Using LC/MALDI-MRM analysis of five tryptic peptides, the protein PHR1 was found to be upregulated in the hyphal (pathogenic) form of C. albicans by a factor of 7.7 ± 0.8. Copyright © 2006 John Wiley & Sons, Ltd.