Title | H/D exchange of gas phase bradykinin ions in a linear quadrupole ion trap |
Publication Type | Journal Article |
Year of Publication | 2003 |
Authors | Mao, DM, Douglas, DJ |
Journal | Journal of the American Society for Mass Spectrometry |
Volume | 14 |
Pagination | 85-94 |
Date Published | Feb |
Type of Article | Article |
ISBN Number | 1044-0305 |
Keywords | ACTIVATED DISSOCIATION, COLLISIONAL ACTIVATION, CYTOCHROME-C, HYDROGEN-DEUTERIUM EXCHANGE, HYDROGEN/DEUTERIUM EXCHANGE, INFRARED, IONIZATION MASS-SPECTROMETRY, OF-FLIGHT SYSTEM, PEPTIDE IONS, PROTEIN IONS, RADIATIVE DISSOCIATION |
Abstract | The gas phase H/D exchange reaction of bradykinin ions, as well as fragment ions of bradykinin generated through collisions in an orifice skimmer region, have been studied with a linear quadrupole ion trap (LIT) reflectron time-of-flight (rTOF) mass spectrometer system. The reaction in the trap takes only tens of seconds at a pressure of few mTorr of D2O or CD3OD. The exchange rate and hydrogen exchange level are not sensitive to the trapping q value over a broad range, provided q is not close to the stability boundary (q = 0.908). The relative rates and hydrogen exchange levels of protonated and sodiated +1 and +2 ions are similar to those observed previously by others with a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer system. The doubly and triply protonated ions show multimodal isotopic distributions, suggesting the presence of several different conformations. The y fragment ions show greater exchange rates and levels than a or b ions, and when water or ammonia is lost from the fragment ions, no exchange is observed. (J Am Soc Mass Spectrom 2003, 14, 85-94) (C) 2003 American Society for Mass Spectrometry. |
URL | <Go to ISI>://000180894500001 |
