This proposal requests funding for acquisition of a new, modern continuous wave (CW) X-band (~9 GHz) electron paramagnetic resonance (EPR) spectrometer, Bruker Elexsys E500 equipped with E560D electron-nuclear double resonance (ENDOR) system, to support the NIH-funded biochemical/biomedical research at the University of Arizona. This spectrometer will be integrated into the existing EPR Facility at the Department of Chemistry and Biochemistry of the University of Arizona, where it will replace the existing aging (~20 years old) Bruker ESP300E CW EPR instrument. The old spectrometer has developed hardware problems, many of its components are completely outdated, and there is a high probability of a critical failure at any time. Such a failure will impede the progress of the projects of the NIH-funded users relying on EPR in their research. The replacement of the old spectrometer by a new, modern one will ensure an uninterrupted access of the users to EPR and will enrich their research capabilities through a significantly (up to an order of magnitude) higher sensitivity of the new instrument and through providing access to CW ENDOR experiments. In short term, this spectrometer will be used in the ongoing biochemical/biomedical research projects of the users who contributed to this proposal. In the long term, this spectrometer will answer the need in EPR experiments of the future NIH-funded researchers and other users of the EPR Facility at the University of Arizona. The specific affected biochemical/biomedical projects described in this proposal include: (1) Using EPR and CW ENDOR to study the molybdenum catalytic center of sulfite-oxidizing enzymes and model synthetic Mo(V) complexes by Dr. J.H. Enemark. This research is important because some point mutations of human sulfite oxidase has fatal consequences;(2) Using EPR for understanding structural and dynamic aspects of chemistry of nitric oxide, NO, which has numerous biological functions important for human health by Drs. F.A. Walker, K.M. Miranda and W.R. Montfort;(3) Using EPR to test the efficiency of newly developed potential cancer drugs suppressing the function of ribonucleotide reductase by Dr. R.T.Dorr;(4) Using EPR to study Cu binding to proteins in relation to metal homeostasis and metal resistance by Dr. M. McEvoy.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biomedical Research Support Shared Instrumentation Grants (S10)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-IMST-B (32))
Program Officer
Levy, Abraham
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Arizona
Schools of Arts and Sciences
United States
Zip Code
Gautam, R; Akam, E A; Astashkin, A V et al. (2015) Sirtuin inhibitor sirtinol is an intracellular iron chelator. Chem Commun (Camb) 51:5104-7
Gautam, Ritika; Loughrey, Jonathan J; Astashkin, Andrei V et al. (2015) Tripyrrindione as a Redox-Active Ligand: Palladium(II) Coordination in Three Redox States. Angew Chem Int Ed Engl 54:14894-7
Astashkin, Andrei V; Chen, Li; Elmore, Bradley O et al. (2015) Probing the Hydrogen Bonding of the Ferrous-NO Heme Center of nNOS by Pulsed Electron Paramagnetic Resonance. J Phys Chem A 119:6641-9
Nelp, Micah T; Astashkin, Andrei V; Breci, Linda A et al. (2014) The alpha subunit of nitrile hydratase is sufficient for catalytic activity and post-translational modification. Biochemistry 53:3990-4
Akam, Eman A; Chang, Tsuhen M; Astashkin, Andrei V et al. (2014) Intracellular reduction/activation of a disulfide switch in thiosemicarbazone iron chelators. Metallomics 6:1905-12
Chang, Tsuhen M; Sinharay, Sanhita; Astashkin, Andrei V et al. (2014) Prodigiosin analogue designed for metal coordination: stable zinc and copper pyrrolyldipyrrins. Inorg Chem 53:7518-26
Klein, Eric L; Belaidi, Abdel Ali; Raitsimring, Arnold M et al. (2014) Pulsed electron paramagnetic resonance spectroscopy of (33)S-labeled molybdenum cofactor in catalytically active bioengineered sulfite oxidase. Inorg Chem 53:961-71
Roy, Anindya; Sarrou, Iosifina; Vaughn, Michael D et al. (2013) De novo design of an artificial bis[4Fe-4S] binding protein. Biochemistry 52:7586-94
Klein, Eric L; Astashkin, Andrei V; Raitsimring, Arnold M et al. (2013) Applications of pulsed EPR spectroscopy to structural studies of sulfite oxidizing enzymes(). Coord Chem Rev 257:110-118
Astashkin, Andrei V; Rajapakshe, Asha; Cornelison, Matthew J et al. (2012) Determination of the distance between the Mo(V) and Fe(III) heme centers of wild type human sulfite oxidase by pulsed EPR spectroscopy. J Phys Chem B 116:1942-50

Showing the most recent 10 out of 11 publications