The Development of an Ion Mobility-Orbitrap Mass Spectrometer for the Analysis of Large Proteins and Protein Complexes
Abstract
Ion mobility-mass spectrometry (IM-MS) is a powerful technique that provides a nested size-and-charge in mass-to-charge analysis in the gas-phase; however, current instrumentation is limited in resolution, both in mobility and mass domains. Recent developments in Orbitrap mass analyzers improve upon the utility of MS by providing improved resolution over current quadrupole and time-of-flight mass analyzers. Orbitraps have catapulted MS into a new field of native MS, the study of solution-phase structures and noncovalent interactions in the gas-phase. Although the power of these new mass analyzers has been realized, coupling of IMS to Orbitraps poses an analytical challenge due to a duty cycle mismatch: Orbitraps detect on a slower timescale than IMS separation, therefore using Orbitraps as a detector for IMS is difficult. Here, a high-resolution periodic focusing drift tube IMS was coupled to an Orbitrap mass analyzer via a novel interface for the biophysical analysis of large proteins and protein complexes. Fourier transform IMS multiplexing was implemented to overcome the duty cycle mismatch between the two platforms and allow for the analyses of native systems.
Finally, the instrument was used to study the structure of a variety of protein complexes and their interactions with small molecules, metals, and posttranslational modifications, all of which have dramatic effects on protein structure, stability, and function.
Citation
Poltash, Michael Lawrence (2019). The Development of an Ion Mobility-Orbitrap Mass Spectrometer for the Analysis of Large Proteins and Protein Complexes. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /200694.