Cardiovascular Biomarkers Discovery by SELDI-TOF Mass Spectrometry

Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (TOF-MS) allows for rapid differential proteomic analysis of various experimental conditions. In the first step of retention chromatography, the proteome to be analyzed is fractionated based on the biochemical properties of the proteins or peptides of which it is composed. TOF-MS separates the proteins according to their molecular mass and charge (m/z in which conditions are optimized to obtain single charged proteins: z = 1). The most discriminating conditions are used to validate differential peaks on a larger number of samples. Once the biomarker is statistically validated, its identification is performed by reproducing the chromatographic conditions that are appropriate for its retention on spin-columns, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, trypsin digestion of the band of interest, and subsequent peptide mapping after MS. It may be necessary to determine part of the amino acid sequence of the protein of interest to confirm its identity.