Our research uses a combination of mass spectrometry and optical spectroscopy to characterize biological molecules in a highly controlled environment - both isolated in the gas phase and in small complexes or clusters. Using these techniques, we can examine the intrinsic properties (such as structure or stability) of isolated biological molecules. Then selected pieces of the local environment (a known number of water molecules, metal ions or binding partners, etc.) can be added back into the system in order to examine the effect of each, separately. These studies provide a bridge between the gas and solution-phase regimes.
In our experimental set-up, gas phase biological ions, complexes or clusters are produced using electrospray ionization (ESI) and then trapped in either a Fourier-transform ion-cyclotron resonance (FT-ICR) mass spectrometer or an electrodynamic ion trap . In addition to traditional trapping mass spectrometry techniques (isolation of ions of the desired mass-to-charge, probing via dissociation reactions or ion/molecule reactions), we are developing gas-phase fluorescence and fluorescence resonance energy transfer (FRET) techniques as a probe of structure.
|We currently have openings for students interested in physical, biological or analytical chemistry. We're looking for people who are interested in learning valuable biological mass spectrometry skills. There will also be the opportunity to develop new techniques combining mass spectrometry and laser spectroscopy. If you are interested, please contact Rebecca at
M. F. Czar and R. A. Jockusch. "Sensitive Probes of Protein Structure and Dynamics in Well-Controlled Environments: Combining Mass Spectrometry with Fluorescence Spectroscopy" Curr. Opin. Struct. Biol., 34C, 123-134, 2015. DOI: 10.1016/j.sbi.2015.09.004.
M. F. Czar, F. Zosel, I. König, D. Nettels, B. Wunderlich, B. Schuler, A. Zarrine-Afsar and R. A. Jockusch, “Gas-phase FRET Efficiency Measurements to Probe the Conformation of Mass-Selected Proteins” Anal Chem., 87, 7559–7565, 2015. DOI 10.1021/acs.analchem.5b01591. (Selected as an ACS Editors’ Choice article)
S.V. Sciuto and R. A. Jockusch, “The intrinsic photophysics of gaseous ethidium ions” J. Photochem. Photobiol. A, 311, 186-192, 2015. DOI 10.1016/j.jphotochem.2015.06.020
S. M. J. Wellman and R. A. Jockusch, “Moving in on the Action: An Experimental Comparison of Fluorescence Excitation and Photodissociation Action Spectroscopy” J. Phys. Chem. A, 119, 6333-6338, 2015. DOI 10.1021/acs.jpca.5b04835.
F.O. Talbot, S.V. Sciuto and R. A. Jockusch, “Fluorescence Imaging for Visualization of the Ion Cloud in a Quadrupole Ion Trap Mass Spectrometer” J. Am. Soc. Mass Spectrom., 24, 1823-1832, 2013. DOI 10.1007/s13361-013-0742-6
M. F. Czar and R. A. Jockusch, “Understanding the Photophysics of Cucurbituril Encapsulation: A Model Study with Acridine Orange in the Gas Phase,” ChemPhysChem, 14, 1138-1148, 2013. DOI 10.1002/cphc.201201008 (Selected for Inside Cover, also highlighted as a VIP paper)
B. L Heath and R. A. Jockusch, “Ligand Migration in the Gaseous Insulin-CB7 Complex: A Cautionary Tale About the Use of ECD-MS for Ligand Binding Site Determination” J. Am. Soc. Mass Spectrom., 23, 1911-1920, 2012. DOI 10.1007/s13361-012-0470-3
A. M. Nagy, F. O. Talbot, M. F. Czar and R. A. Jockusch, “Fluorescence Lifetimes of Rhodamine Dyes in Vacuo” J. Photochem. and Photobiol. A: Chemistry, 244, 47-53, 2012. DOI 10.1016/j.jphotochem.2012.06.017
J. Pan, B. L. Heath, R. A. Jockusch and L. Konermann, “Structural Interrogation of Electrosprayed Peptide Ions by Gas-Phase H/D Exchange and Electron Capture Dissociation Mass Spectrometry” Anal. Chem., 84, 373-378, 2012. DOI 10.1021/ac202730d
F. O. Talbot, A. Rullo, H. Yao and R. A. Jockusch, “Fluorescence Resonance Energy Transfer in Gaseous, Mass-Selected Polyproline Peptides” J. Am. Chem. Soc. 132, 16156-16164, 2010. DOI 10.1021/ja1067405
P. D. McQueen, S. Sagoo, H. Yao and, “On the Intrinsic Photophysics of Fluorescein,” Angew. Chem., 49, 9193-9196, 2010. DOI 10.1002/anie.201004366
Q. Bian, M. W. Forbes, F. O. Talbot and R. A. Jockusch, “Fluorescence Excitation and Emission Spectroscopy of Trapped, Mass-Selected Gas-Phase Ions,” Phys. Chem. Chem. Phys., 12, 2590-2598, 2010. DOI 10.1039/b921076h
M. W. Forbes and R. A. Jockusch, “Deactivation Pathways of a GFP Chromophore Studied by Electronic Action Spectroscopy,” J. Am. Chem. Soc., 131, 17038-17039, 2009. DOI 10.1021/ja9066404