1. Department of Chemistry, University of California, Berkeley, California 94720, United States
2. Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
3. Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, United States
4. Late Stage Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
5. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
6. Materials Sciences Division and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States