Breann L Brown1, T M Iverson2,3. 1. Department of Biochemistry, Vanderbilt University, Nashville, TN, USA. breann.brown@vanderbilt.edu. 2. Department of Biochemistry, Vanderbilt University, Nashville, TN, USA. tina.iverson@vanderbilt.edu. 3. Department of Pharmacology, Vanderbilt University, Nashville, TN, USA. tina.iverson@vanderbilt.edu.