Frontiers in Chemical Physics Symposium - Dr. Stefan Stoll (University of Washington- Dept of Chemistry) "

March 21, 2018: Pulse EPR spectroscopy 1: Determining local electronic and geometric structure via electronnuclear spin couplings

Abstract:  Hyperfine spectroscopy, a sub-family of pulse EPR techniques, quantifies hyperfine couplings between unpaired electron spins and nearby magnetic nuclei. The analysis of these couplings provides rich information about the electronic and geometric structure of  paramagnetic centers. In this presentation, I will introduce the principles of hyperfine spectroscopy and show two exemplary applications to study transition metal complexes. I will briefly highlight our work on increasing the sensitivity and resolution of hyperfine spectroscopy using nanosecond pulse shaping.

March 23, 2018: Pulse EPR spectroscopy 2: Mapping protein conformational landscapes via electron-electron spin couplings

Abstract: Double Electron-Electron Resonance (DEER), a form of pulse EPR spectroscopy, directly measures absolute distances and distance distributions between spin labels on proteins. These data are used to built quantitative structural, energetic, and kinetic models of the protein's intrinsic flexibility, its conformational substates, and its response to external effectors such as ligand binding. In this presentation, I will introduce the fundamentals of DEER spectroscopy. I will summarize our DEER-based biostructural work on HCN, a cardiac ion channel, and I will present our recent work on improving DEER methodologies.