TY - JOUR
T1 - Ion Imaging of Native Protein Complexes Using Orthogonal Time-of-Flight Mass Spectrometry and a Timepix Detector
AU - Mathew, Anjusha
AU - Buijs, Ronald
AU - Eijkel, Gert B
AU - Giskes, Frans
AU - Dyachenko, Andrey
AU - van der Horst, Jerre
AU - Byelov, Dimitry
AU - Spaanderman, Dirk-Jan
AU - Heck, Albert J R
AU - Porta Siegel, Tiffany
AU - Ellis, Shane R
AU - Heeren, Ron M A
PY - 2021/2/3
Y1 - 2021/2/3
N2 - Native mass spectrometry (native MS) has emerged as a powerful technique to study the structure and stoichiometry of large protein complexes. Traditionally, native MS has been performed on modified time-of-flight (TOF) systems combined with detectors that do not provide information on the arrival coordinates of each ion at the detector. In this study, we describe the implementation of a Timepix (TPX) pixelated detector on a modified orthogonal TOF (O-TOF) mass spectrometer for the analysis and imaging of native protein complexes. In this unique experimental setup, we have used the impact positions of the ions at the detector to visualize the effects of various ion optical parameters on the flight path of ions. We also demonstrate the ability to unambiguously detect and image individual ion events, providing the first report of single-ion imaging of protein complexes in native MS. Furthermore, the simultaneous space- and time-sensitive nature of the TPX detector was critical in the identification of the origin of an unexpected TOF signal. A signal that could easily be mistaken as a fragment of the protein complex was explicitly identified as a secondary electron signal arising from ion-surface collisions inside the TOF housing. This work significantly extends the mass range previously detected with the TPX and exemplifies the value of simultaneous space- and time-resolved detection in the study of ion optical processes and ion trajectories in TOF mass spectrometers.
AB - Native mass spectrometry (native MS) has emerged as a powerful technique to study the structure and stoichiometry of large protein complexes. Traditionally, native MS has been performed on modified time-of-flight (TOF) systems combined with detectors that do not provide information on the arrival coordinates of each ion at the detector. In this study, we describe the implementation of a Timepix (TPX) pixelated detector on a modified orthogonal TOF (O-TOF) mass spectrometer for the analysis and imaging of native protein complexes. In this unique experimental setup, we have used the impact positions of the ions at the detector to visualize the effects of various ion optical parameters on the flight path of ions. We also demonstrate the ability to unambiguously detect and image individual ion events, providing the first report of single-ion imaging of protein complexes in native MS. Furthermore, the simultaneous space- and time-sensitive nature of the TPX detector was critical in the identification of the origin of an unexpected TOF signal. A signal that could easily be mistaken as a fragment of the protein complex was explicitly identified as a secondary electron signal arising from ion-surface collisions inside the TOF housing. This work significantly extends the mass range previously detected with the TPX and exemplifies the value of simultaneous space- and time-resolved detection in the study of ion optical processes and ion trajectories in TOF mass spectrometers.
KW - Native mass spectrometry
KW - Orthogonal time-of-flight mass spectrometry
KW - Timepix detector
KW - Ion optics
KW - Single-ion imaging
U2 - 10.1021/jasms.0c00412
DO - 10.1021/jasms.0c00412
M3 - Article
C2 - 33439014
SN - 1044-0305
VL - 32
SP - 569
EP - 580
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
IS - 2
ER -