Wayne State University

Aim Higher



College of Liberal Arts & Sciences
Department of Chemistry
Faculty Page
 
Mary T. Rodgers
Title Professor
Division Analytical (Physical)
Education B.S. Illinois State University 1985
Ph.D. California Institute of Technology 1992
Postdoctoral, California Institute of Technology 1992-94
Postdoctoral, University of Utah 1994-97
Office Chem 29
Phone (313)577-2431
E-Mail
Group http://rodgers.chem.wayne.edu/rodgers
ION Chem http://rodgers.chem.wayne.edu/ionchem
MSPIRE http://rodgers.chem.wayne.edu/pire


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 (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.





REPRESENTATIVE PUBLICATIONS

"Base-Pairing Energies of Protonated Nucleobase Pairs and Proton Affinities of 1-Methylated Cytosines: Model Systems for the Effects of the Sugar Moiety on the Stability of DNA i-Motif Conformation", B. Yang, A. A. Moehlig, C. E. Frieler, M. T. Rodgers, J. Phys. Chem. B 119, 1857-1868 (2015). doi:10.1021/acs.jcpb.5b00035

"Gas-Phase Conformations and Energetics of Protonated 2'-Deoxyadenosine and Adenosine: IRMPD Action Spectroscopy and Theoretical Studies", R.R. Wu, B. Yang, G. Berden, J. Oomens, and M.T. Rodgers, J. Phys. Chem. B 119, 2795-2805 (2015). doi:10.1021/jp509267k

"Guided Ion Beam and Computational Studies of the Decomposition of a Model Thiourea Protein Cross-Linker", R. Wang, B. Yang, R. R. Wu, M. T. Rodgers, M. Schäfer, and P. B. Armentrout, J. Phys. Chem. B 119, 3727-3742 (2015). doi: 10.1021/jp512997z

"Intrinsic Affinities of Alkali Metal Cations for Diaza-18-Crown-6: Effects of Alkali Metal Cation Size and Donor Atoms on the Structure and Binding Energies", C.A. Austin, M.T. Rodgers, Int. J. Mass Spectrom. 377, 65-72 (2015). History of Mass Spectrometry Special Issue. doi:10.1016/j.ijms.2014.06.033

"Infrared Multiple Photon Dissociation Action Spectroscopy of Sodium Cationized Halouracils: Effects of Halogenation on Gas-Phase Conformation", C.M. Kaczan, A.I. Rathur, R.R. Wu, Y. Chen, C.A. Austin, G. Berden, J. Oomens, M.T. Rodgers, J. Am. Soc. Mass Spectrom. 378, 76-85 (2015). Veronica M. Bierbaum Honor Issue. doi:10.1016/j.ijms.2014.07.016

"Base-Pairing Energies of Protonated Nucleoside Base Pairs of dCyd and m5dCyd: Implications for the Stability of DNA i-Motif Conformations", B. Yang, M.T. Rodgers, J. Am. Soc. Mass Spectrom. 26, 1394-1403 (2015). doi:10.1007/s13361-015-1144-8

"On the Mechanism of Phosphodiester Backbone Cleavage in Gaseous RNA", C. Riml, H. Glasner, M.T. Rodgers, R. Micura, K. Breuker, Nucleic Acids Res. 43, 5171-5181 (2015). doi:10.1093/nar/gkv288

"N3 and O2 Protonated Tautomeric Conformations of 2'-Deoxycytidine and Cytidine: Coexist in the Gas Phase", R.R. Wu, B. Yang, C.E. Frieler, G. Berden, J. Oomens, M.T. Rodgers, J. Phys. Chem. B 119, 5773–5784 (2015). doi:10.1021/jp5130316

"Base-Pairing Energies of Proton-Bound Dimers and Proton Affinities of 1-Methyl-5-Halocytosine: Implications for the Stability of the DNA i-Motif”, B. Yang, M.T. Rodgers, J. Am. Soc. Mass Spectrom. 26, 1469-1482 (2015). doi:10.1007/s13361-015-1174-2

"Diverse Mixtures of 2,4-Dihydroxy Tautomers and O4 Protonated Conformers of Uridine and 2-Deoxyuridine Coexist in the Gas Phase", R.R. Wu, B. Yang, C.E. Frieler, G. Berden, J. Oomens, M.T. Rodgers, Phys. Chem. Chem. Phys. 17, 25978 - 25988 (2015). doi:10.1039/c5cp02227d

"Evaluation of Hybrid Theoretical Approaches for Structural Determination of a Glycine-Linked Cisplatin Derivative via IRMPD Action Spectroscopy”, C. C. He, B. Kimutai, X. Bao, Y. Zhu, S. F. Strobehn, J. Gao, G. Berden, J. Oomens, C. S. Chow, M. T. Rodgers, J. Phys. Chem. A 119, 10980-10987 (2015). doi:10.1021/acs.jpca.5b08181

"Discriminating Properties of Metal Alkali Ions towards the Constituents of Proteins and Nucleic Acids. Conclusions from Gas-Phase and Theoretical Studies", M.T. Rodgers, P.B. Armentrout, in Metal Ions in Life Sciences, Springer, Eds. A. Sigel, H. Sigel, and R.K.O. Sigel, 16, 103-131 (2016). https://books.google.com/books?isbn=3319217569

"Minor 2,4-Dihydroxy and O2 Protonated Tautomers of dThd and Thd Coexist in the Gas Phase: Methylation Alters Protonation Preferences vs dUrd and Urd", R.R. Wu, B. Yang, C.E. Frieler, G. Berden, J. Oomens, M.T. Rodgers, J. Am. Soc. Mass Spectrom. 27, 410-421 (2016). doi:10.1007/s13361-015-1303-y

"Mechanisms and Energetics for N-Glycosidic Bond Cleavage of Protonated Nucleosides: 2'-Deoxyguanosine and Guanosine", R.R. Wu, Y. Chen, M.T. Rodgers, Phys. Chem. Chem. Phys. 18, 2968-2980 (2016). doi:10.1039/C5CP05738H

"Interaction of Cu+ with Cytosine and Formation of i-Motif-Like C-M+-C Complexes: Alkali versus Coinage Metals", J. Gao, G. Berden, M. T. Rodgers, and J. Oomens, Phys. Chem. Chem. Phys. 18, 7269-7277 (2016). doi:10.1039/ C6CP00234J

"Ionic Noncovalent Interactions: Energetics and Periodic Trends", M.T. Rodgers and P. B. Armentrout, Chem. Rev. 116, 5642-5687 (2016). doi:10.1021/acs.chemrev.5b00688

"N3 Protonation Induces Base Rotation of 2'-Deoxyadenosine-5'-Monophosphate and Adenosine-5'-Monophosphate", R. R. Wu, He, C. C.; Hamlow, L.; Nei, Y.-w.; Berden, G.; Oomens, J.; and M. T. Rodgers, J. Phys. Chem. B 120, 4616-4624 (2016). doi:10.1021/ acs.jpcb.6b04052

"Protonation Induces Base Rotation of Purine Nucleotides pdGuo and pGuo", R. R. Wu, C. C. He, L. A. Hamlow, Y.-w. Nei, G. Berden, J. Oomens, and M. T. Rodgers, Phys. Chem. Chem. Phys. 18, 15081-15090 (2016). doi:10.1039/C6CP01354F

"O2 Protonation Controls Threshold Behavior for N-Glycosidic Bond Cleavage of Protonated Cytosine Nucleosides", R. R. Wu, M. T. Rodgers, J. Phys. Chem. B 120, 4803-4811 (2016). doi:10.1021/acs.jpcb.6b04388

"Mechanisms and Energetics for N-Glycosidic Bond Cleavage of Protonated Adenine Nucleosides: N3 Protonation Induces Base Rotation and Enhances N-Glycosidic Bond Stability", R. R. Wu, M. T. Rodgers, Phys. Chem. Chem. Phys. 18, 16021 - 16032 (2016). doi:10.1039/C6CP01445C

For a complete list of research publications see http://rodgers.chem.wayne.edu/rodgers/publications.htm

DEPARTMENT OF CHEMISTRY ©
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Phone: (313) 577-7784    Fax: (313) 577-8822

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