ABSTRACT
Mass spectrometry has become one of the most powerful tools for the analysis of proteins. The sample requirements are on the order of 1 pmol to investigate a single protein. The power of the method is due to the fact that it gives fast and accurate information on the molecular weight of the investigated molecule, which can lead to instant identication. In the emerging elds of proteomics and systems biology, mass spectrometry is one of the cornerstone methods. In a typical application, the whole proteome of a cell, as the cell responds to changes in the environment, can be characterized. Modern methods that couple efcient separation techniques with mass spectrometry allow thousands of proteins to be identied in
14.1 ESI ............................................................................................................... 196 14.2 MALDI ....................................................................................................... 197 14.3 Tandem Mass Spectrometry (MS-MS) ....................................................... 198
a single automated experiment from minute samples. It becomes possible to follow the changing proteome qualitatively and, to some extent, also quantitatively. Mass spectrometry also gives important information in the eld of protein-protein interactions.
