文摘
A novel approach is reported for the analysis and identification of proteins separated by 2D-PAGE with scanninginfrared matrix-assisted laser desorption/ionization massspectrometry (scanning IR-MALDI-MS). The proteins ofhuman blood plasma were separated by 2D-PAGE, electroblotted onto PVDF membranes, incubated in matrixsolution, and then scanned by IR-MALDI-MS. Masscontour plots of selected spots were obtained.Proteinseparation is shown to be conserved by comparison withsilver-stained gels. The sensitivity for the proteindetection is comparable if not better than that ofsilver-stainedgels. Posttranslational modifications were identifiedbycomparing the measured mass to the one calculated fromthe known DNA sequence. Adduct formation to unprotected cysteine residues during gel separation is demonstrated for selected proteins.