Investigation of sample-purification procedures for MALDI-based proteomic studies

Purification methods for proteomics samples are of crucial concern for improving the quality of the sample delivered to the mass spectrometer. They constitute the link between the mass spectrometer and protein processing and peptide isolation steps that usually require solvents, buffers, or detergents completely incompatible with MS-analysis conditions. This work describes three new clean-up procedures using synthetic membranes and polymer media and compares them with standard procedures. The efficiency of each of the purification procedures was studied via application to four standards and two membrane proteins. This work highlights the importance of versatility in sample preparation, especially for MS-based proteomic investigations. Figure PMF spectra obtained after MALDI-TOF measurements of bovine mitochondrial complex III (A) and complex IV (B) in-solution digests, with and without purification