1. Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, 1700 4th Street, CA 94143, USA
2. Present Address: Medicines Discovery Catapult, Mereside, Alderley Park, Alderley Edge SK10 4TG, UK
3. Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, 1700 4th Street, CA 94143, USA
4. Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, 1700 4th Street, CA 94143, USA