1. Mass Spectrometry Research Center, Vanderbilt University, Nashville, Tennessee 37203, United States
2. Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37203, United States
3. Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37203, United States
4. Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37203, United States
5. Department of Medicine, Vanderbilt University, Nashville, Tennessee 37203, United States
6. Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37203, United States