Mary T. Rodgers

Mary T. Rodgers

Research interest(s)/area of expertise

Mass spectrometry; infrared spectroscopy; structure and thermochemistry via ion-molecule reactions, collision-induced dissociation, infrared multiple photon dissociation action spectroscopy, and theoretical calculations

Research

Research in the Rodgers group is interdisciplinary in nature, making use of state-of-the-art physical and analytical techniques to study research problems that span all five disciplines of chemistry (i.e., analytical, biochemistry, inorganic, organic, and physical). However, most of the research projects we pursue are of either biological or inorganic relevance and involve the use of model systems. Our research efforts are generally aimed at achieving a better understanding of the interplay between structure and function in biological systems, or structure and intrinsic reactivity in inorganic systems. To this end, we make use of a variety of tandem mass spectrometry (MS/MS) approaches, often enhanced and supported by synergistic theoretical electronic structure calculations, in our research studies.

The primary tools of our research are tandem mass spectrometers (MS/MS) and computers. We currently have three MS/MS instruments available in our experimental arsenal. We also have three high performance liquid chromatographs (HPLC) that can be used independently or in combination with our commercial MS/MS instruments. A variety of supporting tools and instrumentation are also available including: (1) small analytical instruments for sample cleanup and preparation, (2) infrared lasers for complementary photodissociation or spectroscopic studies, (3) software packages for data analysis, and instrument design and control, (4) test and measurement electronics for diagnostics and control, and (5) mechanical tools and hardware. Our research sometimes involves instrument development and modification projects to enable improved MS/MS analyses. We collaborate extensively and thus make use of other MS and laser instrumentation available in the laboratories of our collaborators. Our computational efforts are primarily supported by the Wayne State University High Performance Grid and supplemented by PCs and workstations available in our laboratory. We make extensive use of two commercial computational chemistry software packages to perform relevant electronic structure theory calculations: (1) the Gaussian suite of programs and (2) Hyperchem professional.

Our first MS/MS instrument is a custom-built guided ion beam tandem mass spectrometer of the BOQ geometry (magnetic sector (B) - octopole ion guide (O) - quadrupole mass filter (Q)). This instrument is designed to allow the kinetic-energy dependence of ion-molecule reactions (IMR) or collision-induced dissociation (CID) processes to be examined from thermal to hyperthermal energies. Measured reactant and product intensities are converted to absolute IMR or CID cross sections using Beer’s law. Cross sections are analyzed to extract accurate thermochemical data (i.e., bond dissociation energies (BDEs), activation energies (AEs), heats of reaction (ï„Hrxns). These measurements are supported by complementary theoretical calculations to provide molecule parameters needed for the analysis of experimental data and theoretical estimates for the quantities measured.

Our next MS/MS instrument is a Bruker 7T Solarix Hybrid FTMS (Q-FT-ICR MS). This instrument is our flagship mass spectrometer capable of very high mass accuracy and mass resolution measurements. It is equipped with a variety of ionization sources including: (1) electrospray ionization (ESI) and nano-ESI, (2) matrix assisted laser desorption ionization (MALDI), and (3) chemical ionization (CI and n-CI). It is also equipped with a variety of activation methods including: CID (in-source, Q-CID, SORI-CID), ion-ion reactions (ETD and PTR), ion-electron reactions (ECD and EDD), and photodissociation (IRMPD). It can also be used to perform MS imaging of biological tissues and analytically prepared surfaces in combination with the MALDI source. As a trapping mass spectrometer, it can also be used to make kinetic (e.g., IMR and H/D exchange), equilibrium (e.g., acid-base, ligand exchange, and clustering reactions), and spectroscopic (in combination with tunable lasers) measurements under well-controlled conditions.

Our third MS/MS instrument is a Bruker amaZon ETD quadrupole ion trap mass spectrometer (QITMS). This instrument possesses several of the same capabilities as our FT-ICR MS, but is not capable of nearly as high of mass accuracy or mass resolution measurements. It is equipped with two ionization sources including: (1) ESI and (2) CI and n-CI). It is also equipped with a variety of activation methods including: (1) CID (in-source and multiple collision-CID), (3) ETD and PTR, and (4) IRMPD. Like the FT-ICR MS it is also a trapping MS, and thus can also be used to make kinetic (e.g., IMR and H/D exchange), equilibrium (e.g., acid-base, ligand exchange, and clustering reactions), and spectroscopic (in combination with tunable lasers) measurements, but under somewhat less well controlled conditions than in the FT-ICR MS.

Biomolecule Structure and Stability

Current research projects involve the study of the influence of the local environment (probed via deprotonation, protonation and noncovalent interactions with metal cations or binding of ligand and drug molecules) on the structures and stabilities of biologically relevant systems including: nucleic acids and their component building blocks (nucleobases, nucleosides and phosphate esters and including modifications), proteins and their component building blocks (peptides, amino acids, and post-translational modifications). The mechanisms, energetics and control of fundamental dissociation processes that occur in these systems and the effects of solvation on these systems are also of interest. These studies may lead to a better understanding of various metabolic pathways, provide information to help improve both solution and gas-phase sequencing techniques, and facilitate the development of new drug candidates.

Molecular Recognition

Current research projects involve the study of the factors that lead to strong and selective binding of cations, anions, various types of ligands as well as base-pairing interactions. Structure, size, charge, and the nature and number of donor-acceptor interactions all play a role in determining selectivity and thus are examined. In particular, interactions with macrocyclic ligands and those that lead to noncanonical structures in biological systems are of interest. These studies may help improve characterization, separations, and drug delivery applications.

Solvation

Partially solvated systems are also being studied to enhance our understanding of the effect of solvation on biochemical processes, to provide insight into folding and conformational stability of biological macromolecules, the energetics of solvation, and structural information on the solvated complex. This work also connects the gas-phase tandem MS/MS studies to those performed in condensed-phase environments.

Theoretical Calculations

Theoretical calculations are performed to support and enhance our experimental work and used to obtain model structures and energetics for the species and processes under investigation, to provide insight into the reaction or dissociation mechanisms, and to provide the molecular parameters and IR spectra needed for data analysis.

Education

• B.S., Illinois State University, Chemistry and Mathematics, 1985
• Ph.D., California Institute of Technology, Chemical Physics, 1992
• Postdoctoral, California Institute of Technology, Physical Chemistry/Chemical Physics, Mentor: Jesse (Jack) L. Beauchamp, 1992-94
• Postdoctoral, University of Utah, Physical Chemistry/Chemical Physics, Mentor: Peter B. Armentrout, 1994-97

Awards and grants

• President, Wayne State Academy of Scholars, 2022-23
• Vice President, Wayne State University Academy of Scholars, 2021-22
• Wayne State University Academy of Scholars, 2019
• Among the 66 Female Physical Chemists highlighted in an Editorial in the 150th Birthday of Marie Curie Issue of the Journal of Physical Chemistry B, 2017, 121, 9983–9985, doi: 10.1021/acs.jpcb.7b09653
• Fellow of the American Physical Society, 2016
• Fellow of the American Association for the Advancement of Science, 2010
• Wayne State University Board of Governors Distinguished Faculty Fellowship, 2008
• Wayne State University College of Liberal Arts and Science Excellence in Teaching Award, 2007
• Wayne State University Career Development Award, 2004
• American Society for Mass Spectrometry Research Award, 1998

Selected publications

• “Structural Determination of Lysine-Linked Cisplatin Complexes via IRMPD Action Spectroscopy: Conformers Exhibiting NNs and NO--Binding Modes Coexist”, C.C. He, L.A. Hamlow, H.A. Roy, Z.J. Devereaux, N.A. Cunningham, J. Martens, G. Berden, J. Oomens, and M.T. Rodgers, J. Phys. Chem. B 45, 9246-9260 (2022) pubs.acs.org.doi/pdf/10.1021.acs.jpcb.2c06234
• “5-Halogenation of Uridine Suppresses Protonation-Induced Tautomerization and Enhances Glycosidic Bond Stability of Protonated Uridine: Investigations via IRMPD Action Spectroscopy, ER-CID Experiments, and Theoretical Calculations”, N.M. Mikawy, H.A. Roy, E. Israel, L.A. Hamlow, Y. Zhu, G. Berden, J. Oomens, and M. T. Rodgers, J. Am. Soc. Mass Spectrom. 33, 2165-2180 (2022) pubs.acs.org.doi/pdf/10.1021/jasms.2c00231
• “Influence of 5-Halogenation on the Base Pairing Energies of Protonated Cytidine Nucleoside Analogue Base Pairs: Implications for the Stabilities of Synthetic i-Motif Conformations”, M.T. Rodgers, Y.S. Seidu, and E. Israel, J. Am. Soc. Mass Spectrom. 33, 1697-1715 (2022). Focus Issue in Honor of Peter B. Armentrout. pubs.acs.org/doi/pdf/10.1021/jasms.2c00137
• “Infrared Multiple Photon Dissociation Action Spectroscopy of Protonated Unsymmetrical Dimethylhydrazine and Proton-Bound Dimers of Hydrazine and Unsymmetrical Dimethylhydrazine”, C.P. McNary, M. Demireva, J. Oomens, L.A. Hamlow, M.T. Rodgers, and P.B. Armentrout, PhysChem. Phys. 23, 25877-25885 (2021). pubs.rsc.org/en/content/articlehtml/2021/cp/d1cp03781a
• “Structural Determination of Arginine-Linked Cisplatin Complexes via IRMPD Action Spectroscopy: Arginine Binds to Platinum via NO-Binding Mode”, C.C. He, B. Kimutai, L.A. Hamlow, H.A. Roy, J.K. Martens, G. Berden, J. Oomens, Y.-w. Nei, X. Bao, C.P. McNary, P. Maitre, V. Steinmetz, P.B. Armentrout, C.S. Chow, and M.T. Rodgers, Phys. Chem. Chem. Phys. 23, 21959-21971 (2021). pubs.rsc.org/en/content/articlehtml/2021/cp/d1cp03407c
• “1-Alkyl-3-Methylimidazolium Cation Binding Preferences in Hexafluorophosphate Ionic Liquid Clusters Using Competitive TCID Measurements and Theoretical Calculations”, H.A. Roy and M.T. Rodgers, Phys. Chem. Chem. Phys. Phys. Chem. Chem. Phys. 23, 18145-18162 (2021). pubs.rsc.org/en/content/articlepdf/2021/cp/d1cp02928b
• “Influence of 5-Methylation and the 2′- and 3′-Hydroxy Substituents on the Base-Pairing in Protonated Cytidine Nucleoside Analogue Base Pairs: Implications for the Stabilities of i-Motif Structures”, Y.S. Seidu, H.A. Roy, and M.T. Rodgers, J. Phys. Chem. A 125, 5939-5955 (2021). Published as part of The Journal of Physical Chemistry virtual special issue “125 Years of The Journal of Physical Chemistry.” pubs.acs.org/doi/10.1021/acs.jpca.1c04303
• “Nature and the Strength of Intrinsic Cation Anion Interactions of 1-Alkyl-3-Methylimidazolium Hexafluorophosphate Clusters” H.A. Roy and M.T. Rodgers, Phys. Chem. Chem. Phys. 23, 13405-13418 (2021). doi.org/10.1039/D1CP01130H
• “Absolute Trends and Accurate and Precise Gas-Phase Binding Energies of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters from Combined Independent and Competitive TCID Measurements”, H. A. Roy and M. T. Rodgers, J. Phys. Chem. A 124, 10199-10215 (2020). pubs.acs.org/doi/abs/10.1021/acs.jpca.0c07246
• “Gas-Phase Binding Energies and Dissociation Dynamics of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters”, H.A. Roy, L.A. Hamlow, and M. T. Rodgers, J. Phys. Chem. A 124, 10181-10198 (2020). pubs.acs.org/doi/abs/10.1021/acs.jpca.0c06297
• “Influence of the Local Environment on the Intrinsic Structures of Gas-Phase Cytidine-5'-Mononucleotides”, L.A. Hamlow, Y.-w. Nei, R.R. Wu, J. Gao, J.D. Steill, G. Berden, J. Oomens, and M.T. Rodgers, Int. J. Mass Spectrom. 447, 116234 (2020). doi.org/10.1016/j.ijms.2019.11623
• “Amino Acid-Linked Platinum (II) Compounds: Non-canonical Nucleoside Preferences and Influence on Glycosidic Bond Stabilities”, B. Kimutai, C.C. He, A. Roberts, M.L. Jones, X. Bao, J. Jiang, Z. Yang, M.T. Rodgers, and C.S. Chow, J. Biol. Inorg. Chem. 24, 985-997 (2019). link.springer.com/article/10.1007/s00775-019-01693-y
• “Structural and Energetic Effects of 2'-Ribose Methylation of Protonated Pyrimidine Nucleosides”, C.C. He, L.A. Hamlow, Y. Zhu, Y.-w. Nei, L. Fan, C.P. McNary, P. Maitre, V. Steinmetz, B. Schindler, I. Compagnon, P.B. Armentrout, and M.T. Rodgers, J. Am. Soc. Mass Spectrom., 30, 2318-2334 (2019). https://pubs.acs.org/doi/abs/10.1007/s13361-019-02300-9
• “Impact of Sodium Cationization on Gas-Phase Conformations of DNA and RNA Cytidine Mononucleotides”, L.A. Hamlow, Y.-w. Nei, R. R. Wu, J. Gao, J.D. Steill, G. Berden, J. Oomens, and M. T. Rodgers, J. Am. Soc. Mass Spectrom., 30, 1758-1767 (2019). link.springer.com/article/10.1007%2Fs13361-019-02274-8
• “Infrared Multiple Photon Dissociation Action Spectroscopy of Protonated Glycine, Histidine, Lysine, and Arginine Complexes with 18-Crown-6 Ether”, C.P. McNary, Y.-w. Nei, Philippe Maitre, M.T. Rodgers, and P. B. Armentrout, Phys. Chem. Chem. Phys. 21, 12625-12639 (2019). pubs.rsc.org/en/content/articlelanding/2019/cp/c9cp02265a#!divAbstract
• “Structures and Relative Glycosidic Bond Stabilities of Protonated 2'-Fluoro Substituted Purine Nucleosides”, Z.J. Devereaux, C.C. He, Y. Zhu, H.A. Roy, N.A. Cunningham, L.A. Hamlow, G. Berden, J. Oomens, and M.T. Rodgers, J. Am. Soc. Mass Spectrom. 30, 1521-1536 (2019). link.springer.com/article/10.1007%2Fs13361-019-02222-6

Citation index

h-index = 53, i-10 index = 125 (last updated March 12, 2023)

Courses taught by Mary T. Rodgers

Fall Term 2024 (future)

• CHM6160 - Separation Science
• CHM7160 - Separation Science

Winter Term 2024 (current)

• CHM3120 - Analytical Chemistry

Fall Term 2023

• CHM6160 - Separation Science
• CHM7160 - Separation Science

Winter Term 2023

• CHM6180 - Mass Spectrometry
• CHM7180 - Mass Spectrometry

Fall Term 2022

• CHM5160 - Instrumental Analytical Chemistry

Winter Term 2022

• CHM3120 - Analytical Chemistry