Weighing naked proteins: practical, high-accuracy mass measurement of peptides and proteins.

Two new technologies have made the study of proteins by mass spectrometry straight-forward. Proteins with molecular masses of up to more than 100 kilodaltons can be analyzed at picomole sensitivities to give simple mass spectra corresponding to the intact molecule. This development has allowed unprecedented accuracy in the determination of the molecular weights of proteins. A number of "case studies" are used to present the revolutionary impact that these powerful new ways of looking at proteins are having on biological research.