The Bush Lab is a research group in the Department of Chemistry and the Biological Physics, Structure & Design Program at the University of Washington. Our research focuses on the development and application of mass spectrometry and ion mobility spectrometry techniques to elucidate the structures and assembly of protein complexes and subcellular machines.
The Bush Lab welcomes Chrissy Stachl! Click here to learn more about Chrissy.
Ion Mobility Mass Spectrometry: New Instrumentation & Enabling Technologies
Matthew F. Bush presiding
Tuesday, June 11th at 5:45 PM | Room 205 AB
The performance of conventional and differential ion mobility mass spectrometers has escalated dramatically in recent years, which can be attributed to improved separations, more efficient ion transfer, and tighter integration of ion mobility devices into hybrid instruments. These improvements enable intricate and sensitive experiments probing mobility selected or separated ions, which has led to the adoption of ion mobility technologies in a wide range of applications, including challenges in gas-phase ion structure determination, native mass spectrometry, proteomics, and systems biology. We will showcase the latest developments in ion mobility mass spectrometry instrumentation and discus remaining challenges.
Prof. Stephen Valentine (West Virginia University)
Miniaturization of Overtone Ion Mobility Spectrometry
Dr. Guillermo Vidal-de-Miguel (SEADM)
Developments in Transversal Modulation IMS (TMIMS): an Add-on enabling absolute IMS-IMS pre-filtration in tandem with MS, and providing 100% DC
Dr. Dimitris Papanastasiou (Fasmatech)
Implementation of a novel Differential Mobility Spectrometry Platform in the Fore Vacuum Region of a Mass Spectrometer
Dr. Melvin Park (Bruker)
High Resolution Trapped Ion Mobility Spectrometry and the Beginnings of a Theory
Dr. Yehia Ibrahim (Pacific Northwest National Laboratory)
The development of the PNNL IMS platform: challenges and solutions
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Alicia Schwartz and Cindy Wei will each present posters at the 16th Annual UW Undergraduate Research Symposium on Friday, May 16th. Their posters will on Easels 135 and 136 in Mary Gates Hall 241 from 2:30 PM to 4:00 PM. Protein Complexes … Continue reading
Gas-phase conformations and electron transfer dissociations of pentapeptide ions containing the photo-Leu residue (L*) were studied. Exhaustive conformational search including molecular dynamics force-field, semi-empirical, ab initio, and density functional theory calculations established that the photo-Leu residue did not alter the gas-phase conformations of (GL*GGK + 2H)2+ and (GL*GGK-NH2 + H)+ ions, which showed the same conformer energy ranking as the unmodified Leu-containing ions. This finding is significant in that it simplifies conformational analysis of photo-labeled peptide ions. Electron transfer dissociation mass spectra of (GL*GGK + 2H)2+, (GL*GGK-NH2 + 2H)2+,(GL*GGKK + 2H)2+, (GL*GLK + 2H)2+, and (GL*LGK + 2H)2+ showed 16 %–21 % fragment ions originating by radical rearrangements and cleavages in the diazirine ring. These side-chain dissociations resulted in eliminations of N2H3, N2H4, [N2H5], and [NH4O] neutral fragments and were particularly abundant in long-lived charge-reduced cation-radicals. Deuterium labeling established that the neutral hydrazine molecules mainly contained two exchangeable and two nonexchangeable hydrogen atoms from the peptide and underwent further H/D exchange in an ion–molecule complex. Electron structure calculations on the charge-reduced ions indicated that the unpaired electron was delocalized between the diazirine and amide π* electronic systems in the low electronic states of the cation-radicals. The diazirine moiety in GL*GGK-NH2was calculated to have an intrinsic electron affinity of 1.5 eV, which was further increased by the Coulomb effect of the peptide positive charge. Mechanisms are proposed for the unusual elimination of hydrazine from the photo-labeled peptide ions.
Electron Transfer Dissociation of Photolabeled Peptides. Backbone Cleavages Compete with Diazirine Ring Rearrangements Aleš Marek, Robert Pepin, Bo Peng, Kenneth J. Laszlo, Matthew F. Bush, František Tureček. J. Am. Soc. Mass Spectrom. 2013, DOI:10.1007/s13361-013-0630-0. (Link|PUBMED)
We just received our second mass spectrometer, a Waters Synapt HDMS, quadrupole/ion-mobility/time-of-flight hybrid mass spectrometer.