1. Department of Chemistry, University of California, Berkeley, California 94720, United States
2. Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
3. Process Development, Attribute Sciences, Amgen Inc., Thousand Oaks, California 91320, United States
4. Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
5. Department of Molecular and Cellular Biology, University of California, Berkeley, California 94720, United States
6. California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, United States