Monitoring structural changes of proteins in an ion trap over approximately 10-200 ms: unfolding transitions in cytochrome c ions.
A new technique for studying the time dependence of conformational changes of gas-phase protein ions is described. In this approach, a short pulse of electrosprayed protein ions is introduced into an ion trap and stored. After a defined time period, the distribution of ions is ejected from the trap into an ion mobility/time-of-flight mass spectrometer. Combined measurements of mobilities and flight times in the mass spectrometer provide information about the abundances of different conformer types and charge-state distributions. By varying the storage time in the trap, it is possible to monitor changes in ion conformation that occur over extended time periods (approximately 10-200 ms). The method is demonstrated by examining changes in cytochrome c ion conformations for the +7 to +10 charge states.
Badman
E R
ER
Department of Chemistry, Indiana University, Bloomington 47405, USA.
Hoaglund-Hyzer
C S
CS
Clemmer
D E
DE
D000818:Animals; D003574:Cytochrome c Group / Q000737:chemistry*; D006736:Horses; D009206:Myocardium / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
D003574:Cytochrome c Group