1. Center for Biophysics and Quantitative Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
2. Department of Biochemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
3. Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
4. Neuroscience Program, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
5. Beckman Institute, University of Illinois at Urbana−Champaign 600 South Mathews Avenue, Urbana, Illinois 61801, United States