With this award from the Chemistry Research Instrumentation and Facilities: Departmental Multi-User Instrumentation program (CRIF:MU), Professor Mark Cracolice and colleagues Bruce Bowler, Michele McGuirl, Edward Rosenberg and Valeriy Smirnov from University of Montana will acquire an X-band EPR spectrometer. The proposal is aimed at enhancing research training and education at all levels, especially in areas of study such as (a) the role of protein dynamics in folding and function, (b) characterization of amino acid radicals and copper binding to deseases states of prions, (c) oxidation of protein-bound amino acid residues, (d) surface-immobilized luminescent and redox-active ruthenium complexes, (e) radicals produced during metabolism of chromium(V and VI), and (f) mechamism of Ric-8A-catalyzed guanine nucleotide exchange at heterotrimeric G protein alpha subunits.
An EPR spectrometer yields detailed information on the geometric and electronic structure of molecular and solid state materials. It may also be used to obtain information about the lifetimes of free radicals, short-lived, highly reactive species involved in valuable chemical transformations as well as the initiation of pathological tumor growth. These studies will impact a number of areas, from the synthesis of inorganic and organic molecules to the development of new solid state materials to compounds of biological interest. Employing examples inspired from ongoing research, this instrument will be an integral part of research and teaching at the undergraduate and graduate levels.
The purpose of this project was the acquisition of an electron paramagnetic resonance (EPR) spectrometer by the Department of Chemistry and Biochemistry for use in research and education on the Missoula campus of the University of Montana. A Bruker EMXplus instrument was purchased. It is a simple and rugged instrument, well-tested for routine hands-on use by the researchers and students of varied levels of experience: from undergraduate students to post-doctoral associates. This instrument allows for observation of signals from paramagnetic samples over a wide magnetic field range with high resolution and high sensitivity. The instrument was installed and currently is in use by the students and faculty of the University of Montana. Intellectual Merit. Using this instrument, four independent research groups conduct studies involving formation and characterization of unstable reactive species in enzymes, biological molecules, and inorganic samples. For example, one group investigates the conversion of the prion protein (PrP) from its normal monomeric state to an amyloid fibril form. These studies are accomplished by monitoring the EPR signals of modified PrPs particularly suitable for EPR. Another group investigates formation of the protein-centered radicals in an enzyme linked to immunosuppression and cancer - indoleamine 2,3-dioxygenase (IDO). The radicals are being generated in IDO in response to oxidative stress. The radicals may also be involved in normal function of the enzyme. These studies require low temperature EPR because generally these radicals are unstable and convert into other species. Broader Impact. The EPR instrument is also being used for educational activities. For example, students in the Advanced Biochemistry Laboratory class had prepared site-directed mutants of azurin and expressed the protein in Escherichia coli. Some students then monitored changes at the copper center as a function of pH and guanidine concentration using changes in Cu(II) EPR signals. There is a link between improvements to infrastructure and the increase in representation of women and members of underrepresented groups in tenure-track and tenured positions at the University. Together with the recently-acquired MALDI-ToF mass spectrometer, the EPR instrument improves departmental biophysical spectroscopy infrastructure. This enhances the ability to conduct cutting-edge research on campus and helps with recruiting, hiring, and retention of talented researchers. This affects not only the Department of Chemistry and Biochemistry, but also other Departments and Divisions that have interdepartmental ties with Chemistry through such means as the Center for Biomolecular Structure and Dynamics (CBSD), the Interdepartmental Biochemistry Program, and the Native American Research Laboratory (NARL).
