1. Chemical Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
2. Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
3. Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA
4. Departments of Medicinal Chemistry, Pharmacology, and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
5. Department of Biochemistry and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA