1. Program in Biomolecular Pharmacology, Boston University School of Medicine, 72 East Concord Street, Boston, Massachusetts 02118, United States
2. Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
3. Department of Biological Chemistry, University of Michigan, 5220E MSRB III 1150 West Medical Center Drive, Ann Arbor, Michigan 48109, United States