In our research, we seek to solve problems pertaining to the chemistry of some life processes involving iron, such as cellular iron uptake and regulation, biological oxidation, nitrogen binding and fixation and hydrogen generation. We study aspects of the mechanism, structures of the intermediates and model complexes for these processes. The bulk of our experimental work involves Mössbauer and EPR spectroscopy. Our Mössbauer spectroscopy laboratory was established in 2004 with funds from an NSF-MRI grant (Popescu, 2004-07).
Some of our current interdisciplinary projects are listed below. We have been funded by the National Science Foundation, most recently in 2021, by the Molecular & Cellular Biosciences Division in the BIO Directorate. In the past, our lab received funding, between 2010-13 and 2013-2017, from the Chemistry of Life Processes (CLP) Program in the MPS Directorate.
All the projects in the Popescu Lab involve solely undergraduate students and are in various stages of planning or accomplishment. For the latter, see our publications list.
- Studies of iron-sulfur proteins, cellular iron trafficking and regulation.(see Image attached)
- Studies of model complexes for Fe(III)-radical model complexes for aminophenol oxidases and for cysteine dioxygenase.
- Characterization of novel Fe(I) and other unusual bio-inspired complexes.
- Studies of the dual-function enzyme dehaloperoxidase (DHP) from Amphitrite ornata.
- Studies of iron complexes exhibiting spin transitions.
- The study of novel complexes that aim to model the active site of hydrogenase enzymes.
These projects combine spectroscopic characterization of iron bio-inspired complexes with the analysis of enzyme active sites, calculations and biochemical characterization of enzymes, such as DHP. These collaborative projects involve world-class scientists, both synthetic chemists and biochemists, from Louisiana State University, Marquette University, University of Delaware, North Carolina State University (Raleigh), and Texas A&M.
Recent Developments in the Mössbauer Spectroscopy of Iron-Sulfur Proteins
In collaboration with Dr. Huangen Ding and his group from Louisiana State, Dr. Popescu's lab at The University of St. Thomas, to gain insight into the function of the Fur protein. In bacteria, the global regulator called the ferrum uptake regulator (Fur) regulates iron homeostasis, by controlling its uptake and storage. Yet, the mechanism by which Fur executes its function is not well understood.
Isolating the Fur protein from E. coli and sending it to St. Thomas to be analyzed by Mössbauer spectroscopy revealed the presence of a [2Fe-2S] cluster in Fur. Fe-S clusters are ubiquitous structures with diverse functions in biology and sometimes they are chemical sensors for iron, oxygen or other small molecules. Undergraduate Kate Valdes and Dr. Popescu at St. Thomas collected and analyzed the Mössbauer spectra, while graduate students Chelsey Fontenot and Homyra Tasnim in Dr. Ding's lab at LSU conducted the biochemical studies.
The findings were published in a collaborative paper in the Journal of Biological Chemistry (JBC), which has Chelsey Fontenot as lead author. The paper was selected as Editor's Pick in November 2020, a distinction that recognizes the top two (2) percent of manuscripts JBC editors will review in a year in significance and overall importance. About 50 to 100 papers are selected from the more than 6,600 JBC publishes each year. A commentary about the paper appeared in the same issue of JBC and a subsequent news piece in ASBMB Today, the magazine of the American Society for Biochemistry and Molecular Biology. (see web links BELOW)
- Popescu, C. V.; Dinh, T.; Chen, H.; Miller, D.; Washburn, A.; McGuire, A.; Dumarieh, R.; D'Antonio, J.; Ghiladi, R. A., Mössbauer studies of the ferryl, ferrous, and ferric states of the dehaloperoxidase from A. ornata. J. Inorg. Biochem. 2022, 234, 111867.
- Wang,P., Saber, M., VanNatta, P., Yap, G., Popescu, C.V., Scarborough, C., Kieber-Emmons, M., Dunbar, K., Riordan, C. G. "Molecular and electronic structures, and single-molecule magnet behavior of tris(thioether)-iron complexes containing redox-active α-diimine ligands" Inorg. Chem. (2021) 60 (9) 6480-6491. DOI: 10.1021/acs.inorgchem.1c00214
- Ekanayake, D.E, Fischer, A.A, *Elwood, M.E, Guzek, A.M, Lindeman, S.V, Popescu, C.V., Fiedler, A.T. "Nonheme Iron-Thiolate Complexes as Structural Models of Sulfoxide Synthase Active Sites" Dalton Trans. (2020) 49, 17745-17757. DOI: 1039/D0DT03403G (*Maya Elwood is an undergraduate student)
- Fontenot, C.R., Tasnim, H. *Valdes, K.A., Popescu, C.V., Ding, H. "Ferric uptake regulator (Fur) reversibly binds a [2Fe-2S] cluster to sense intracellular iron homeostasis in Escherichia coli" Biol. Chem. (2020) 295, 15454-15463. DOI: doi.org/10.1074/jbc.RA120.014814 (*Kate Valdes is an undergraduate student) EDITOR'S PICK!
- Kephart, J.A., Hecht, Z.H., Livesay, B.N., Shores, M.P., Popescu, C.V., Arulsamy, N., Hulley, E.B."Self-assembly of an Organometallic Fe₉O₆ Cluster from Aerobic Oxidation of (tmeda)Fe(CH₂tBu)₂" Chem. Comm. (2020) 56 (37) 4994-4997. DOI: 10.1039/D0CC00011F
- Gordon, Z., Miller, .T.J., Leahy, C.A., Matson, E.M., Burgess, M., Drummond, M.J., Popescu, C.V., *Smith, C.M., Lord, R.L., Rodríguez-López, J., Fout, A.R. Chem. (2019) Inorg. Chem. (2019) 58 (23) 15801–15811. DOI: 10.1021/acs.inorgchem.9b02079. (*Connor Smith is an undergraduate student)
- Popescu, C.V., Ding, S., Ghosh, P., Hall, *Cohara, M. Mössbauer Spectroscopic and Theoretical Studies of bimetallic complexes showing electrocatalytic hydrogen evolution Chem. (2019) 58 (10) 7069-7077. DOI: 10.1021/acs.inorgchem.9b00746. (*Morgan Cohara was an undergraduate student)
- Drummond, M. J., Ford, C. J., Gray, D. G., Popescu, C. V., Fout, A. R. Radical Rebound Hydroxylation Versus H-Atom Transfer in Non-Heme Iron(III)-Hydroxo Complexes: Reactivity and Structural Differentiation Am. Chem. Soc. (2019) 141 (16), 6639–6650. DOI: 10.1021/jacs.9b01516.
- Wang, P.; Killian, M.; Saber, M.; Qiu, T.; Yap, G.; Popescu, C. V.; Rosenthal, J.; Dunbar, K. R.; Brunold, T.; Riordan, C.G. “Electronic, Magnetic, Redox Properties and O2 Reactivity of Fe(II) and Ni(II)-o-Semiquinonate Complexes of a Tris(thioether) Ligand: Uncovering the Intradiol Cleaving Reactivity of an Fe(II)-o-semiquinonate Complex” Chem. (2017) 56 (17), 10481–10495; DOI: 10.1021/acs.inorgchem.7b01491.
- Prokopchuk, D.E., Wiedner, E.S, Walter, E.D., Popescu, C.V., Piro, N.A., Kassel, W.S.A., Bullock, M, Mock, M. T. Structure and reactivity of Iron Coordination Complexes toward Dinitrogen “Catalytic N2 Reduction into Silylamines and Thermodynamics of N2 Binding at Square Planar Fe” Am. Chem. Soc. (2017),139, 9291–9301; DOI: 10.1021/jacs.7b04552.
- Tichnell, C. R., Shultz, D. A. Popescu, C.V., *Sokirnyi, I, Boyle, P.D. “Synthesis, Characterization and Photophysical Studies of an Iron(III) Catecholate-Nitronylnitroxide Spin-Crossover Complex” I Chem. (2015) 54 (9), 4466–4474.
- Bittner, M.M., Lindeman, S.V., Popescu, C.V., Fiedler, T “Dioxygen Reactivity of Biomimetic Fe(II) Complexes with Noninnocent Catecholate, o-Aminophenolate, and o-Phenylenediamine Ligands” Inorg. Chem. (2014), 53 , 4047-4061.
- Hsieh, C.H.; Erdem, O.; Ding, S.; Crouthers, D.; Lubitz, W.; Popescu, C.V.; Reibenspies, J.; Hall, M. B. Darensbourg, M. Y. “Redox active iron nitrosyl units in proton reduction electrocatalysis” Nature Communications (2014) 5, 3684.
- Stoian, S., Hsieh, C.-H.;* Casuras, A.; Singleton, M.L., Darensbourg, M.Y., *McNeely, K.M., *Sweely, K., Popescu, C.V. “Hyperfine Interactions and Electron Distribution in FeIIFeI and FeIFeI Models for the Active Site of the [FeFe]-Hydrogenases”, Biol. Inorg. Chem., (2013) 18: 609-622 http://link.springer.com/article/10.1007/s00775-013-1005-5#page-1}
- Hsieh, C.-H.; Brothers, S.M.; Hall, M.B.; Popescu, C.V.; Darensbourg, M.Y., “The Ambidentate Thiocyanate Ligand in Dinitrosyl Iron Complexes”, Chem. (2013), 52(4): 2119-2124.
- Bittner, M.M., *Kraus, D., Lindeman, V., Popescu, C.V., Fiedler, A.T “Synthetic, Spectroscopic, and DFT Studies of Iron Complexes with Iminobenzo(semi)quinone Ligands: Implications for o-Aminophenol Dioxygenases” Chem. Eur. J. (2013), 19(29): 9686-98
- Hsieh, C.-H., Harman, S. D., Singleton, M.L., Reijersee, E.; Lubitz, W.; Popescu, C.V., Brothers, S.M., Reibenspies, J.H., Hall, M.B., Darensbourg, M.Y. "Structural and Spectroscopic Features of Mixed Valent FeIIFeI Complexes and Factors Related to the Rotated Configuration of Diiron Hydrogenase” Am. Chem. Soc. (2012), 134, 13089-13102.
- Liu, T., Li, B., Popescu, C.V., *Bilko, A., Perez, L., Hall, M. B., Darensbourg, M, Y. “Analysis of an Iron Dicarbonyl as Synthetic Analogue of the Hmd or [Fe]-Hydrogenase Active Site” Eur. J. (2010), 16, 3083-3089.
- Popescu, C.V., Mock, M.T., Stoian, S.A., Riordan, C.G. “A high-spin organometallic Fe-S compound: Structural and Mössbauer Spectroscopic Studies of [Phenyltris((tert-butylthio)methyl)borate]Fe(Me), Chem. (2009) 48 (17), 8317-8324.
- Li, B., Liu, T., Popescu, C.V., *Bilko, A., Darensbourg, M, Y. “Synthesis and Mössbauer Characterization of Octahedral Iron(II) Carbonyl Complexes FeI2(CO)3L and FeI2(CO)2L2: Developing Models of the [Fe]-H2ase Active Site” Inorganic Chemistry (2009), 48 (23), 11283-11289.
- Mock, M.T., Kieber-Emmons, M.T., Popescu, C.V., *Gasda, P., Yap, G.P.A., Riordan, C.G. “A Series of Cyanide-Bridged Binuclear Complexes”, Chim. Acta (2009) 362, 4553-4562.
- Mock, M.T., Popescu, C.V., Yap, G.P.A., Dougherty, W.G., Riordan, C.G. “Monovalent Iron In a Sulfur-rich Environment”, Chem. (2008), 47 (6), 1889-1891.
- Zhang, J., Wallar, B.J., Popescu, C.V., Renner, D.B, Thomas, D.D., Lipscomb, J.D. “Methane Monooxygenase Hydroxylase and B Component Interactions” Biochemistry 2006 45, 2913-2926.
- Wolfe, M. D., Altier, D. J., Stubna, A., Popescu, C. V., Münck, E., Lipscomb, J. D. “Benzoate 1,2-Dioxygenase from Pseudomonas putida: Single Turnover Kinetics and Regulation of a Two Component Rieske Dioxygenase”, Biochemistry 2002, 41(30), 9611-9626.
- Popescu, C. V., Münck, E., Fox, B. G, Sanakis, Y., Cummings, J. G., Turner, I. M., Jr., Nelson M. J. “Mössbauer and EPR Studies of the Photoactivation of Nitrile Hydratase”, Biochemistry 2001, 40, 7984-7991.
- Münck, E., Popescu, C. V. “Mössbauer Studies of Exchange Coupled Cluster Assemblies in Biological Systems” Hyperfine Interactions 2000, 126, 59- 67.
- Bates, D. M., Popescu, C. V., Koroshilova, N.; Vogt, K., Beinert, H. Münck, E., Kiley, P. J. “Substitution of Lucine 28 for Histidine in the E. coli Transcription Factor FNR Results in Increased Stability of the [4Fe-4S]2+ Cluster to Oxygen”, Biol. Chem. 2000, 275, 6234.
- Popescu, C. V., Münck, E. “On the electronic structure of the H-cluster in [Fe]-Hydrogenases”, Am. Chem. Soc. 1999, 121, 7877.
- Popescu, C. V., Bates, D. M., Beinert, H., Münck, E., Kiley, P. J. (1999) “Mössbauer studies of the FNR transcription factor in whole E. Coli cells”, in Iron Metabolism, Wiley-VCH
- Kyritsis, P., Kümmerle, R., Huber, J. G., Gaillard, J., Guigliarelli, B., Popescu C. V., Münck, E., Moulis, J. -M. “Unusual NMR, EPR, and Mössbauer Properties of Chromatium vinosum 2[4Fe-4S] Ferredoxin”, Biochemistry 1999, 38, 6335.
- Popescu, C. V., Bates, D. M., Beinert, H., Münck, E., Kiley, P. J. (1999) “Mössbauer studies of the FNR transcription factor in whole Coli cells”, in Iron Metabolism, Wiley-VCH.
- Popescu, C. V., Bates D. M., Münck E., Beinert, H., Kiley, P. J. “Mössbauer Spectroscopy as a Tool for the Study of Activation/Inactivation of the Transcription regulator FNR in whole Cells of Escherichia coli”, Nat. Acad. Sci. USA 1998, 95, 13431.
- Kauffmann, K., Popescu, C. V., Dong, Y., Lipscomb, J. D., Que, L. Jr, Münck, E. “Mössbauer Evidence for Antisymmetric Exchange in a Diferric Synthetic Complex and Diferric Methane Monooxygenase”, Am. Chem. Soc. 1998, 120, 8739.
- Hsu, H., Koch, S. A., Popescu, C. V., Münck, E. “Chemistry of Fe Thiolate Complexes with CN- and CO. Models for the [Fe(CO)(CN)2] Structural Unit in Ni-Fe Hydrogenase Enzymes”, Am. Chem. Soc. 1997, 119, 8371.
- Khoroshilova, N., Popescu, C. V., Münck, E., Beinert, H., Kiley, P. J. “Iron-sulfur cluster disassembly in the FNR protein of Escherichia coli by O2: [4Fe-4S] to [2Fe-2S] conversion with loss of biological activity”, Natl. Acad. Sci USA 1997, 94, 6087.
- Xia, J., Hu, Z., Popescu, C. V., Lindahl, P. A., Münck, E. “Mössbauer and EPR Study of the Ni-Activated Metallosubunit of Carbon Monoxide Dehydrogenase from Clostridium thermoaceticum”, Am. Chem. Soc. 1997, 119, 8301.
The ACS National Meeting – April 5 - 16, 2021, Virtual Meeting; Mössbauer Studies of Model Complexes for Short-Lived Intermediates of Cysteine Dioxygenases. Popescu, C. V., *Maya Elwood, *Anastasia Washburn, Praveen Kumar and Adam Fiedler.
ICBIC 19, The International Conference on Biological Inorganic Chemistry – 2019, Interlaken, Switzerland; Mössbauer studies of model complexes for intermediates in the catalytic cycle of mononuclear non-heme iron dioxygenases. Popescu, C. V., Fiedler, A., Kumar, P., Valdes, K.A.
The 53rd Midwest Regional Meeting of the American Chemical Society –October 2018, Ames, IA, MWRM-169; Mössbauer Studies of Mitochondrial and prokaryotic iron-sulfur proteins. Valdes, K., Popescu, C. V., Ding, H.
The 253rd ACS National Meeting –August 2017,San Francisco; Mössbauer Spectroscopy of Iron- Selone and and Iron-Thione Complexes Capable of Preventing Oxidative DNA Damage. Popescu, C. V.; *Morgan Cohara; Stadelman, B.; Brumaghim, J.
EUROBIC 13, The European Biological Inorganic Chemistry Conference – 2016, Budapest, Hungary; Mössbauer and Theoretical Studies of Bimetalic Complexes containing Metal-Nitroxide units. Popescu, C. V.; Shengda Ding; Pokhraj Gosh; Marcetta Y. Darensbourg.
Bucknell University, The Chemistry Seminar Series – March 29, 2016, Lewisburg, PA, Mössbauer Studies of Iron Complexes with Hydrogen-Evolving Activity. Popescu, C. V.
Colgate University – The Natural Sciences Division Colloquium, Spring 2016 – Analyzing Molecules with Mössbauer Spectroscopy to reveal Iron’s Catalytic Power. Popescu, C.V.
The 251st ACS National Meeting – San Diego, 2016; Mössbauer Spectroscopy and Electronic Structure of Iron-Nitrosyl Complexes. Popescu, C. V.; Pokhraj Gosh; *Morgan Cohara; Marcetta Y. Darensbourg.
The 250th ACS National Meeting – Boston, August, 2015; Mössbauer Studies of multimetallic assemblies of complexes with different spin states. Popescu, C. V.; Pokhraj Gosh; *Kaye Kuphal; *Nicholas Baglieri; Marcetta Y. Darensbourg.
The 248th ACS National Meeting – San Francisco, August, 2014; Mössbauer Studies of the ferryl, ferrous, and ferric states of the dehaloperoxidase from Amphitrite ornata. Popescu, C. V.; Barrios, David; *Miller, Danielle B.; Ghiladi, Reza A.
The 248th ACS National Meeting – San Francisco, August, 2014; Mössbauer Studies of a low-spin monovalent iron complex; Popescu, C. V.; Wang, P.; *DeHont, Raymond; Mock, Michael T.; Riordan, Charles G.
The 248th ACS National Meeting – San Francisco, August, 2014; Mössbauer and Magnetometry Studies of a ferric complex with spin transition. Popescu, C. V.; *Sokirnyi, Ivan; Tichnell, Christopher; Shultz, David.
The 247th ACS National Meeting – Dallas, March, 2013; Mössbauer Studies of the dual-function protein Dehaloperoxidase. Popescu, C. V., *Danielle Miller, Reza Ghiladi
The International Conference on Biological Inorganic Chemistry – ICBIC 16 – Grenoble, France, July 21-26, 2013: Hyperfine Interactions in the 2Fe subcluster of the [Fe-Fe] hydrogenases. Popescu, C. V., S. Stoian, *A. Casuras, C.-H. Hsieh, M. Singleton, M. Y. Darensbourg.
The 244th ACS National Meeting – Philadelphia, PA August 19-23, 2012; Mössbauer Studies of mixed-valence FeIIFeI and FeIFeI model complexes illustrating states of the H-cluster in the [Fe-Fe]-hydrogenases. C. V. Popescu, S. Stoian, A. Casuras, C.-H. Hsieh, M. Singleton, M. Y. Darensbourg.(INOR-49)
The 244th ACS National Meeting – Philadelphia, PA August 19-23, 2012; Mössbauer Studies of model complexes for the [Fe-Fe]-hydrogenases: Electronic Structure of Mixed-Valent Complexes Containing Low-Spin FeI. C. V. Popescu, S. Stoian, A. Casuras, C.-H. Hsieh, M. Singleton, M. Y. Darensbourg. (INOR-699)
The 244th ACS National Meeting – Philadelphia, PA August 19-23, 2012; Mössbauer Studies of the enzyme dehaloperoxidase from A. ornata. D. Miller, C. V. Popescu, J. Birabaharan, R. Dumarieh, R. Ghiladi. (CHED-178)
Gordon Research Conference: Iron-Sulfur Enzymes, Mount Holyoke College, Massachusetts, June 10-14, 2012: Mössbauer Studies of Low-spin Monovalent Iron and the Mixed-Valence Fe(II)Fe(I) Oxidized state of the [Fe-Fe]-Hydrogenases, C. V. Popescu, S. Stoian, A. Casuras, C.-H. Hsieh, M. Singleton, M. Y. Darensbourg.
"The Villanova University Physics Colloquium", February 12, 2012 - "Mössbauer studies of monovalent iron in search for a good model for the hydrogenase" C. V. Popescu.
The International Conference on Biological Inorganic Chemistry – ICBIC 15 – Vancouver, Canada, August 6 – 13, 2011; "Mössbauer studies of model complexes illustrating different states of the H-cluster in [Fe-Fe] hydrogenases" C. V. Popescu, S. Stoian, A. Casuras, M. Singleton, M. Y. Darensbourg.
The 239th ACS National Meeting – Boston, MA, August 16-20, 2010; "Advances in the characterization of discrete states of the hydrogenase active site" C. V. Popescu, A. Bilko, M. Singleton, M. Y. Darensbourg.
Gordon Research Conference: Iron-Sulfur Enzymes, Colby-Sawyer College, New Hampshire, June 6-11, 2010; "Mössbauer studies of model complexes for the active site of the Fe-only hydrogenases" C. V. Popescu, Marcetta Darensbourg, Michael Singleton, Andrey Bilko.
The 238th ACS National Meeting – Washington, D.C., August 16-20, 2009;
“Mössbauer Studies of a high-spin ferrous organometallic complex”, C. V. Popescu,M. T. Mock, S. A. Stoian, C. G. Riordan.
The International Conference on Biological Inorganic Chemistry – ICBIC 13 – Vienna, Austria, July 15 – 22, 2007. “Synthetic, structural and Mössbauer studies of novel high-spin iron complexes supported by a tri-thioether ligand” - C. V. Popescu, M. Mock, S. A. Stoian and C. G. Riordan.
The National CUR Conference – De Pauw, Indiana, June 22-26, 2006; “Mössbauer spectroscopy: challenge and opportunity for undergraduate researchers” – C.V. Popescu, Michael Mock, Charles Riordan.
The Bryn Mawr - Haverford Chemistry Colloquium, October 28, 2005 - "Mössbauer studies of model compounds for the active sites of hydrogenases and Carbon Monoxide Dehydrogenase" Popescu, C. V.
International Conference on Biological Inorganic Chemistry – ICBIC 12 – Ann Arbor, Michigan, July 31-August 5, 2005; Poster: Mössbauer studies of the effects of ligand binding and redox changes in the active center of the [NiFe]-hydrogenase from Allochromatium vinosum - Popescu, C. V., Surerus, K. K., Ravi, N., Duin, E., Roseboom, W., Münck, E. and Albracht, S.P.J.
The 228th ACS National Meeting - Philadelphia, August 22-26, 2004; “57Fe - Mössbauer spectroscopic studies of model compounds for the Fe-only hydrogenases”, DeHont, R. F.; Chiarella, G.; Melgarejo, D.; Stoian, S.; Koch, S.; Münck, E.; Popescu, C. V.
The National CUR Conference – La Crosse, Wisconsin, June 16-22, 2004 – “Fluorescence and Mössbauer spectroscopic studies of biologically relevant systems” – C.V. Popescu, Raymond DeHont.
The 10th International Workshop in ESR Spectroscopy and Imaging – April 2003, Fukuoka, Japan – “Mutagenesis and ESR studies of the component interactions in the methane monooxygenase from M. trichosporium” Popescu, C.V., Cornea, R. L., Lipscomb, J. D., Thomas, D. D.
Biophysical Society National Meeting – 2003 “Fluorescence studies of the component interactions in Methane Monooxygenase from M. trichosporium OB3b” Popescu, C.V., Lipscomb, J.D., Thomas, D.D. Biophys. J. Abstracts.
International Conference for Bioinorganic Chemistry – ICBIC 11 - Florence, Italy, 2001 “Mössbauer and EPR Studies of the Photoactivation of Nitrile Hydratase” - Popescu, C.V., Münck, E., Fox, B. G, Sanakis, Y., Cummings, J. G., Turner, I. M., Jr., Nelson M. J.
National Science Foundation Award - NSF-MCB Standard Grant starting in 2021
Project Title: Collaborative Research: The ferric uptake regulator (Fur) regulates intracellular iron homeostasis via reversible binding of a [2Fe-2S] cluster in Escherichia coli (Collaborative research with Dr. Huangen Ding, at Louisiana State University, Baton, Rouge, LA)
Past Awards
2014-2017: National Science Foundation – RUI: Mössbauer Studies of Iron Containing Model complexes and enzymatic active sites ($ 189,000) – CHE-1445959;
2013-2014: National Science Foundation – RUI: Mössbauer Studies of Iron Containing Model complexes and enzymatic active sites - CHE-1307650
2010-2014: National Science Foundation – RUI: Mössbauer Studies of Iron Containing Model complexes and enzymatic active sites ($ 165,000) – CHE-0956779
2004-2007: National Science Foundation – Major Research Instrumentation Award for Acquisition of a Mössbauer Spectrometer at Ursinus College ($124,000) – MRI-0421116
2002-2003: NIH Ruth Kirschstein National Research Service Award for post-doctoral research – Structural Dynamics of Methane Monooxygenase by Nitroxide-EPR and Fluorescence Energy Transfer (FET).