1. Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
2. Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
3. Program
in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
4. Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
5. Department
of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States