1. Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida 32610, Center for Biophysical Modeling and Simulations and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, EMBL Grenoble-Outstation, 6 Rue Jules Horowitz BP156, 38042 Grenoble, France, and Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida 32610