Recent News

Posted on

Recent Semiars

Prof. Bush recently presented the following seminars:

Posted on

New Publication: Ion Mobility of Peptide Ions

Ion Mobility of Peptide Ions

One difficulty in using ion mobility (IM) mass spectrometry (MS) to improve the specificity of peptide ion assignments is that IM separations are performed using a range of pressures, gas compositions, temperatures, and modes of separation, which makes it challenging to rapidly extract accurate shape parameters. We report collision cross section values (Ω) in both He and N2 gases for 113 peptide ions determined directly from drift times measured in a low-pressure, ambient temperature drift cell with radio-frequency (rf) ion confinement. These peptide ions have masses ranging from 231 to 2969 Da, ΩHe of 89–616 Å2, and ΩN2 of 151–801 Å2; thus, they are ideal for calibrating results from proteomics experiments. These results were used to quantify the errors associated with traveling-wave Ω measurements of peptide ions and the errors concomitant with using drift times measured in N2 gas to estimate ΩHe. More broadly, these results enable the rapid and accurate determination of calibrated Ω for peptide ions, which could be used as an additional parameter to increase the specificity of assignments in proteomics experiments.

Ion Mobility Mass Spectrometry of Peptide Ions: Effects of Drift Gas and Calibration Strategies Matthew F. Bush, Iain D. G. Campuzano, Carol V. Robinson. Anal. Chem. 2012, 84, 7124–7130.

Posted on

Bush Lab at the Cascadia Proteomics Symposium

Cascadia Proteomics Symposium

The Bush Lab and collaborators are presenting the following talks at the Cascadia Proteomics Symposium, which takes place at the Institute for Systems Biology in Seattle from July 19-21.

  • Samuel T. Marionni; Weiman Xing; Ning Zheng; Matthew F. Bush. Ion Mobility Mass Spectrometry of a Circadian Clock Protein Complex Reveals a Ligand-Dependent Conformational Switch (Thursday @ 4:40 pm)
  • Samuel J. Allen; Samuel T. Marionni; Kevin Giles; Tony Gilbert; Matthew F. Bush. Design and Characterization of a New Ion Mobility Cell (Saturday @ 9:50 am)
Posted on

New Publication: Dissecting Heterogeneous Molecular Chaperone Complexes

Small heat-shock proteins (sHSPs) are molecular chaperones that prevent irreversible aggregation through binding nonnative target proteins. Due to their heterogeneity, the resulting sHSP:target complexes remain poorly understood. We developed a general and automated approach for estimating the distribution of stoichiometries for heterogeneous ensembles of protein complexes. Using this approach, we find that the stoichiometries of sHSP:target complexes depend on both the mass and quaternary architecture of the target, indicating that protection occurs early during denaturation. This investigation therefore explains the apparent paradox of how variable, complex morphologies result from the generic sHSP protection mechanism.

For a perspective on this work, please see Breaking Down Order to Keep Cells Tidy, a preview written by Christine Slingsby and Alice Clark (Birkbeck College).

Dissecting Heterogeneous Molecular Chaperone Complexes Using a Mass Spectrum Deconvolution Approach Florian Stengel, Andrew J. Baldwin, Matthew F. Bush, Gillian R. Hilton, Hadi Lioe, Eman Basha, Nomalie Jaya, Elizabeth Vierling, Justin L.P. Benesch. Chem. Biol. 2012, 19, 599–607.

Posted on

New Publication: Ion Mobility Mass Spectrometry of Human Insulin Oligomers

The collision cross-section (Ω) of a protein or protein complex ion can be measured using traveling-wave (T-wave) ion mobility (IM) mass spectrometry and calibration with compounds of known Ω. Obtaining accurate T-wave Ω-values via calibration, especially for native-like protein ions, remains challenging. Using human insulin oligomer ions we show how to select appropriate calibration standards, find the optimal instrument settings, and validate the resulting T-wave Ω-values. We also probe subtle conformational differences between human insulin and insulin aspart, a fast-acting insulin analog.

These results are also useful for calibrating other ion mobility experiments, particularly for ions of smaller, native-like proteins and protein complexes. Those values have been added to our collision cross section database.

Traveling-wave ion mobility mass spectrometry of protein complexes: accurate calibrated collision cross-sections of human insulin oligomers Rune Salbo, Matthew F. Bush, Helle Naver, Iain Campuzano, Carol V. Robinson, Ingrid Pettersson, Thomas J. D. Jørgensen, Kim F. Haselmann. Rapid Commun. Mass Spectrom. 2012, 26, 1181–1193.

Posted on

Bush Lab at ASMS

asms_vancouverThe Bush Lab and collaborators are presenting the following posters at the American Society for Mass Spectrometry annual meeting in Vancouver. Abstracts may be found by searching at for “Bush” using the conference planner.

  • Samuel J. Allen; Samuel T. Marionni; Kevin Giles; Tony Gilbert; Matthew F. Bush. Design and Characterization of a New Ion Mobility Cell for Protein Complexes (Monday, Poster 634)
  • Samuel T. Marionni; Weiman Xing; Ning Zheng; Matthew F. Bush. Ion Mobility Mass Spectrometry of a Circadian Clock Protein Complex Reveals a Ligand-Dependent Conformational Switch (Wednesday, Poster 244)
  • Lucas Monkkonen; Yue Huang; Sung Hwan Yoon; John Edgar; Eri Nakatani; Carlos E. Catalano; Matthew F. Bush; David R. Goodlett. Native Mass Spectrometry of Noncovalent Protein Complexes by Surface Acoustic Wave Nebulization (Tuesday, Poster 261)

Matt Bush and Brandon Ruotolo will also co-chair the Ion Mobility MS Workshop on Applying Ion Mobility-Mass Spectrometry to Challenges in Proteomics and Systems Biology (Wednesday, 5:45-7:00, Room 220-222).

  • Utilizing IMS-MS Separations in Proteomic Studies Erin Baker (Pacific Northwest National Labs)
  • Strategies and Challenges in Dynamic Systems Biology Analysis Using Structural Mass Spectrometry Jeffrey R. Enders, Christina C. Marasco, Kevin T. Seale, John P. Wikswo, John A. McLean (Vanderbilt University)
  • Realization of the Promise of IM-MS in Differential Expression Proteomics Erik J. Soderblom, J. Will Thompson, Matt W. Foster, Meredith E. Turner, M. Arthur Moseley (Duke University)
  • Quantitative IM-MS^E Proteomics Brent Martin (University of Michigan)

We look forward to seeing everyone in Vancouver!