Recent News

Interpreting the Collision Cross Sections of Native-Like Protein Ions: Insights from Cation-to-Anion Proton-Transfer Reactions. Kenneth J. Laszlo, Matthew F. Bush. Anal. Chem. 2017, DOI: 10.1021/acs.analchem.7b01474. (Link)

The effects of charge state on structures of native-like cations of serum albumin, streptavidin, avidin, and alcohol dehydrogenase were probed using cation-to-anion proton-transfer reactions (CAPTR), ion mobility, mass spectrometry, and complementary energy-dependent experiments. The CAPTR products all have collision cross-section (Ω) values that are within 5.5% of the original precursor cations. The first CAPTR event for each precursor yields products Continue reading “New Publication: Interpreting the Collision Cross Sections of Native-Like Protein Ions: Insights from Cation-to-Anion Proton-Transfer Reactions”

Structural Dynamics of Native-Like Ions in the Gas Phase: Results from Tandem Ion Mobility of Cytochrome c. Samuel J. Allen, Rachel M. Eaton, Matthew F. Bush. Anal. Chem. 2017, DOI: 10.1021/acs.analchem.7b01234. (Link)

Ion mobility (IM) is a gas-phase separation technique that is used to determine the collision cross sections of native-like ions of proteins and protein complexes, which are in turn used as restraints for modeling the structures of those analytes in solution. Here, we evaluate the stability of native-like ions using tandem IM experiments implemented using structures for lossless ion manipulations (SLIM). In this implementation of tandem IM, ions undergo a first dimension of IM up to a switch that is used to selectively transmit ions of a desired mobility. Selected ions are accumulated in a trap and then released after a delay to initiate the second dimension of IM. For delays ranging from 16 to 33 231 ms, Continue reading “New Publication: Structural Dynamics of Native-Like Ions in the Gas Phase: Results from Tandem Ion Mobility of Cytochrome c”

Effects of Solution Structure on the Folding of Lysozyme Ions in the Gas-Phase. Kenneth J. Laszlo, Eleanor B. Munger, Matthew F. Bush. J. Phys. Chem. B 2017, 121, 2759–2766. (Link)

The fidelity between the structures of proteins in solution and protein ions in the gas phase is critical to experiments that use gas-phase measurements to infer structures in solution. Here we generate ions of lysozyme, a 129-residue protein whose native tertiary structure contains four internal disulfide bonds, from three solutions that preserve varying extents of the original native structure. We then use cation-to-anion proton-transfer reactions (CAPTR) to reduce the charge states of those ions in the gas phase and ion mobility to probe their structures. The collision cross section (Ω) distributions of Continue reading “New Publication: Effects of Solution Structure on the Folding of Lysozyme Ions in the Gas-Phase”

Julia Greenwald, a first year graduate student in the Bush Lab, was recently awarded a National Science Foundation Graduate Research Fellowship! From the NSF:

The NSF Graduate Research Fellowship Program recognizes and supports outstanding graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based Master’s and doctoral degrees at accredited United States institutions. (For additional information, click here.)

Prof. Bush has been named the recipient of the 2017 Arthur F. Findeis Award for Achievements by a Young Analytical Scientist. The Findeis Award is given annually by the American Chemistry Society Division of Analytical Chemistry, to recognize and encourage outstanding contributions to the fields of analytical chemistry by a young analytical scientist. The award will be presented at the 254th ACS National Meeting to be held August 20-24, 2017 in Washington DC. (Link to additional information about the award)

Native-like and Denatured Cytochrome c Ions Yield Cation-to-Anion Proton-Transfer Products with Similar Collision Cross Sections. Kenneth J. Laszlo, John H. Buckner, Eleanor B. Munger, Matthew F. Bush. J. Am. Soc. Mass Spectrom. 2017, in press. (Link)

The relationship between structures of protein ions, their charge states, and their original structures prior to ionization remains challenging to decouple. Here, we use cation-to-anion proton transfer reactions (CAPTR) to reduce the charge states of cytochrome c ions in the gas phase, and ion mobility to probe their structures. Ions were formed using a new temperature-controlled nanoelectrospray ionization source Continue reading “New Publication: Native-Like and Denatured Cytochrome c Ions Yield Cation-to-Anion Proton Transfer Reaction Products with Similar Collision Cross-Sections”

The Bush Lab welcomes Daniele Canzani! Click here to learn more about Daniele.

Effects of drift gas selection on the ambient-temperature, ion mobility mass spectrometry analysis of amino acids. Kimberly L. Davidson and Matthew F. Bush. Anal. Chem. 2017, DOI: 10.1021/acs.analchem.6b04605. (Link)

Ion mobility (IM) separates ions based on their response to an electric field in the presence of a drift gas. Due to its speed and sensitivity, the integration of IM and mass spectrometry (MS) offers many potential advantages for the analysis of small molecules. To determine the effects that drift gas selection has on the information content of IM separations, absolute collision cross sections (Ω) with He, N₂, Ar, CO₂, and N₂O were measured for the 20 common amino acids using low-pressure, ambient-temperature ion mobility experiments performed in a radio-frequency-confining drift cell. Continue reading “New Publication: Effects of drift gas selection on the ambient-temperature, ion mobility mass spectrometry analysis of amino acids”