1. Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois.
2. Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois.
3. Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois.
4. Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois.