Protein/Peptide Sequence Analysis by Mass Spectrometry
The determination of protein and polypeptide primary structure has always been an important area of research in biochemistry. The use of mass spectrometry for elucidation of polypeptide primary structure has also found broad application, and can be used in situations where the Edman technique fails, as, for example, when the polypeptide has a blocked N-terminus. Within the broad area of mass spectrometry exists a variety of methodologies that can be applied to the molecular analysis of polypeptides and proteins. Of all the mass spectrometric techniques in use today for polypeptide structure determinations, fast atom bombardment, or FAB analysis, is employed most often. In field desorbtion mass spectrometry, an underivatized polypeptide sample is desorbed by means of a heated and electrically charged filament in order to obtain its mass spectrum. The resulting mixture is then converted into volatile derivatives suitable for analysis by gas chromatography-mass spectrometry (GC-MS).