1. Department
of Chemistry, University at Buffalo, Buffalo, New York 14221, United States
2. Department
of Chemistry, Durham University, Durham DH1 3EL, U.K.
3. Department
of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602, United States
4. Department
of Chemistry, Yale University, New Haven, Connecticut 06520, United States
5. Department
of Chemistry and Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, United States
6. Departments
of Biological Sciences and Chemistry, Purdue University, West Lafayette, Indiana 47907, United States