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Targeted comparative proteomics by liquid chromatography/matrix‐assisted laser desorption/ionization triple‐quadrupole mass spectrometry
Author(s) -
Melanson Jeremy E.,
Chisholm Kenneth A.,
Pinto Devanand M.
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2391
Subject(s) - chemistry , chromatography , mass spectrometry , sample preparation in mass spectrometry , selected reaction monitoring , electrospray ionization , triple quadrupole mass spectrometer , protein mass spectrometry , top down proteomics , tandem mass spectrometry , matrix assisted laser desorption/ionization , ion suppression in liquid chromatography–mass spectrometry , electrospray , liquid chromatography–mass spectrometry , surface enhanced laser desorption/ionization , analytical chemistry (journal) , desorption , adsorption , organic chemistry
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 a 1 ion in tandem mass (MS/MS) spectra of all peptides studied. Therefore, the a 1 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.