1. Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
2. Department of Pathology, Microbiology, and Immunology and Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
3. Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405-7102, United States