ANYL 222 |
| Using high-field asymmetric waveform ion mobility spectrometry (FAIMS), mixtures of ions, such as those often formed directly by electrospray ionization, can be rapidly separated with high sensitivity. Isomers and conformers that have identical mass can often be separated and individually transmitted into a mass spectrometer making FAIMS a largely orthogonal method to mass spectrometry. Here, results of separation of isomers and protein conformers with FAIMS, with subsequent molecular characterization using electron capture dissociation (ECD) are shown. We find that the shape of the molecule can have a greater effect on electron capture efficiency than either collisional cross section or charge state alone. The cleavage locations of different conformers of given charge state of the protein ubiquitin are the same indicating that the presence of different conformers in the gas phase is not due to differences in where charges are located, but rather reflect conformational differences most likely originating from solution. We also find that the abundances of fragments formed by ECD of different conformers can be significantly different and that some information about solution-phase conformation can be inferred from these gas-phase measurements. |
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Bioanalytical Applications of Ion Mobility Mass Spectrometry, Supported by Waters Corporation
8:30 AM-12:05 PM, Tuesday, 12 September 2006 Moscone Center -- Room 124, Oral
Division of Analytical Chemistry |