1. Department of Medicine, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38165, USA.
2. Department of Chemistry, Earlham College, 801 National Road West, Richmond, IN 47374, USA.
3. Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA.
4. University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37830, USA.
5. Department of Chemistry, Tennessee Technological University, 55 University Drive, Cookeville, TN 38501, USA.
6. Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.