Mass spectrometry of proteins and peptides: sensitive and accurate mass measurement and sequence analysis.

The study of proteins and peptides by mass spectrometry has been advanced by the development of matrix-assisted laser desorption/ionization and electrospray ionization. Proteins with masses > 100 kDa may be measured accurately at picomole sensitivities. Sequence analysis of peptides in mixtures at subpicomole quantities is possible by tandem mass spectrometry. Practical applications of the new technology to biological research are illustrated.