The objective of this application is to request a Bruker BioSpin Corporation Elexsys E560 continuous-wave electron paramagnetic resonance (EPR) spectrometer with 10"""""""" electromagnet/12 kW power supply that will operate at X-band (9-10 GHz) and Q-band (34 GHz) microwave frequencies, and include the electron-nuclear double resonance (ENDOR, TRIPLE) accessories for X- and Q-band. Also requested are cryostats for operation at liquid helium and nitrogen temperature, to adjust to the different relaxation properties of the paramagnets, and a goniometer for single crystal studies. The new instrument would replace an aging EPR spectrometer system. The user group includes the PI, an experienced EPR spectroscopist, and three other Major Users and two Minor Users. The instrument will support the NIH-funded research of four users (5 R01 grants), the pending NIH-funded research of one user, and the preliminary studies of another. The proposed EPR/ENDOR projects include the following: (a) determination of the molecular mechanism of electrondeficient radical-mediated catalysis in coenzyme B12-dependent enzymes, (b) investigation of the emergent novel biological functions of iron-sulfur clusters in biotin synthase, pyruvate-formate lyase activating enzyme, and ferredoxin:thioredoxin reductase, in combination with Mossbauer spectroscopy, (c) the mechanism of biotransformation of aromatic hydrocarbons by toluene monooxygenases, by examining metal site structure in single crystals in combination with protein X-ray crystallography, (d) the structure and function of flavoenzymes, (e) determination of the role of divalent metals in the mechanism of fibrillogenesis in amyloid formation, and (f) characterization of the mechanism of radical-mediated DNA strand scission and histone modification by novel organometallic complexes. Operation at Q-band is justified by the need for enhanced resolution of both EPR and ENDOR spectra, and the dual X- and Q-band operation is essential for success of multi-frequency approaches to constrain spectral simulation analyses. The projects supported by the requested EPR spectrometer cover investigations of the wide range of recognized biological radical reactivity, from """"""""programmed"""""""" essential radicals in enzymes, to deleterious effects of free radicals and metals, to the use of radical reactivity as a therapeutic tool. A sustained high impact of the EPR spectrometer on biomedicine is therefore anticipated.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biomedical Research Support Shared Instrumentation Grants (S10)
Project #
1S10RR017767-01
Application #
6582101
Study Section
Special Emphasis Panel (ZRG1-SSS-A (02))
Program Officer
Tingle, Marjorie
Project Start
2003-04-01
Project End
2005-03-31
Budget Start
2003-04-01
Budget End
2005-03-31
Support Year
1
Fiscal Year
2003
Total Cost
$261,405
Indirect Cost
Name
Emory University
Department
Physics
Type
Schools of Arts and Sciences
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Nforneh, Benjamen; Bovell, Adonis M; Warncke, Kurt (2018) Electron spin-labelling of the EutC subunit in B12-dependent ethanolamine ammonia-lyase reveals dynamics and a two-state conformational equilibrium in the N-terminal, signal-sequence-associated domain. Free Radic Res 52:307-318
Ucuncuoglu, Neslihan; Warncke, Kurt (2018) Protein Configurational States Guide Radical Rearrangement Catalysis in Ethanolamine Ammonia-Lyase. Biophys J 114:2775-2786
Nforneh, Benjamen; Warncke, Kurt (2017) Mesodomain and Protein-Associated Solvent Phases with Temperature-Tunable (200-265 K) Dynamics Surround Ethanolamine Ammonia-Lyase in Globally Polycrystalline Aqueous Solution Containing Dimethyl Sulfoxide. J Phys Chem B 121:11109-11118
Wang, Miao; Zhu, Chen; Kohne, Meghan et al. (2015) Resolution and Characterization of Chemical Steps in Enzyme Catalytic Sequences by Using Low-Temperature and Time-Resolved, Full-Spectrum EPR Spectroscopy in Fluid Cryosolvent and Frozen Solution Systems. Methods Enzymol 563:59-94
Wang, Miao; Warncke, Kurt (2013) Entropic origin of cobalt-carbon bond cleavage catalysis in adenosylcobalamin-dependent ethanolamine ammonia-lyase. J Am Chem Soc 135:15077-84
Hernández-Guzmán, Jessica; Sun, Li; Mehta, Anil K et al. (2013) Copper(II)-bis-histidine coordination structure in a fibrillar amyloid ?-peptide fragment and model complexes revealed by electron spin echo envelope modulation spectroscopy. Chembiochem 14:1762-71
Robertson, Wesley D; Bovell, Adonis M; Warncke, Kurt (2013) Cobinamide production of hydrogen in a homogeneous aqueous photochemical system, and assembly and photoreduction in a (??)8 protein. J Biol Inorg Chem 18:701-13
Chen, Hanlin; Sun, Li; Warncke, Kurt (2013) Heterogeneous ordered-disordered structure of the mesodomain in frozen sucrose-water solutions revealed by multiple electron paramagnetic resonance spectroscopies. Langmuir 29:4357-65
Bovell, Adonis Miguel; Warncke, Kurt (2013) The structural model of Salmonella typhimurium ethanolamine ammonia-lyase directs a rational approach to the assembly of the functional [(EutB-EutC)ýýý]ýýý oligomer from isolated subunits. Biochemistry 52:1419-28
Gunderson, William A; Hernández-Guzmán, Jessica; Karr, Jesse W et al. (2012) Local structure and global patterning of Cu2+ binding in fibrillar amyloid-? [A?(1-40)] protein. J Am Chem Soc 134:18330-7

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