Mass mapping of cancer cell lysates using two-dimensional liquid separations, electrospray-time of flight-mass spectrometry, and automated data processing

Intact protein masses from immortal, nontransformed MCF10A, a human breast epithelial cell line, and its malignant derivative MCF10CA1a.cl1 have been mapped using a combination of all-liquid separations and automated data interpretation. Preparative liquid isoelectric focusing combined with nonporous silica reverse-phase high-performance liquid chromatography allows efficient separation of a large number of proteins in complex mixtures such as whole-cell lysates. Molecular weight determination of these proteins is achieved using electrospray-time of flight-mass spectrometry, however, manual data analysis for these separations is both complex and time-consuming. Protein mass mapping can be significantly enhanced by automating deconvolution functions typically performed manually, with resulting reductions in hands-on analysis time from 20-30 h per chromatogram to approximately 15 min. This reduction in analysis time allows for rapid screening of cancer cell lines for potential biomarkers over a wider pI range than would otherwise be possible.