1. Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
2. Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA, 19104, USA
3. Department of Biochemistry and Biophysics, Oregon State University, 2011 Ag Life Sciences Building, Corvallis, Oregon, 97331, USA
4. Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific St., Box 357290, Seattle, WA, 98195, USA