| 摘要 |
The invention relates to the structural analysis of proteins in the molecular mass range from approximately 5 to 100 kilodaltons, without prior enzymatic digestion to small peptides, in mass spectrometers that operate with ion traps. Since the ionization of large proteins by electrospraying or similar processes always creates highly charged analyte ions, the invention combines fragmentation of the analyte ions with partial deprotonation. It is favourable to apply deprotonation prior to fragmentation, although the invention is not restricted to this. The aim is to generate the most evenly distributed mixture possible of fragment ions having between one and n charges, where n is a number between three and about eight. From this mixture of fragment ions it is possible to record a mass spectrum which demonstrates a sequence coverage that far exceeds the mass range of the mass analyzer for singly charged ions. Both ergodic and electron-induced fragmentation may be carried out. |
