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 he electron paramagnetic resonance (EPR) facility has been recently moved from the School of Life Sciences to a spacious new home in the Department of Chemistry and Biochemistry (PS C2). The EPR facility is equipped with a Bruker ELEXSYS spectrometer operating at S-band (ER 061 CW, 3.8 GHz) and X-band (E580 CW/pulse, 9.4 GHz) frequencies. The setup at X-band is multipurpose and allows performing the complete repertoire of CW and pulse EPR techniques (ENDOR, ESEEM and HYSCORE). These techniques are ideal to characterize the electronic and spatial structure of paramagnetic species. There are several cryostats to perform experiments using either liquid nitrogen or liquid helium as cryogens.
The EPR facility will receive two additional units at the end of this semester. These are the microwave bridge (Super Q-FT) and the pulse ELDOR (E580-400U) upgrade units. The new bridge will allow our Bruker ELEXSYS spectrometer to operate at Q-band (34 GHz) frequencies increasing three times the resolution of the pulse EPR experiments. In addition, pulse ELDOR experiments, which are used to measure the distance between two paramagnetic species, will be available at X-band and Q-band frequencies.
The EPR facility has traditionally supported the faculties associated with the Center of Bioenergy and Photosynthesis. Their research is mainly focused on the study of radicals, radical pairs, triplet states and transition metal complexes involved in bioenergetics and related model systems. However, we are willing to establish new collaborations with faculties associated with other centers or institutes at Arizona State University (e.g. the Biodesign Institute). EPR technology is now an important tool in biophysical research for medical application. For instance, the role of oxygen and reactive oxygen species (e.g. NO) in cardiovascular physiology and disease can be investigated using EPR technology. The results of such studies can contribute to the prevention and treatment of lipid abnormalities, atherosclerosis and cardiac mortality.
Furthermore, the use of spin labels enables the application of EPR technology to systems (e.g. proteins or enzymes) in which the reaction mechanism does not involve a paramagnetic species. In particular, pulse ELDOR spectroscopy is an ideally suited technique to monitor conformational changes in proteins (or enzymes) by measuring the dipole-dipole interaction, i.e. the distance, between two spin labels specifically introduced in the protein by site-direct mutagenesis.
The EPR facility is currently collaborating with Professors Kevin Redding, James Allen, Anne Jones, Jens Appel and Ana Moore. Please, contact Marco Flores (mafloresr@asu.edu) for further information.
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