Photoionization of a protein isolated in vacuo
Résumé
Gas phase VUV single-photon photoionization spectroscopy of electrospray-produced multiply protonated cytochrome c protein ( 12 kDa) has been performed by means of coupling a linear quadrupole ion trap with a synchrotron beamline. The thresholds for the ionization of the 8+ and 11+ charge state precursors to radical 9+ and 12+ species were measured to be 12.75 +/- 0.10 and 13.51 +/- 0.10 eV, respectively.