1. Department
of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
2. IBM Research, Zurich, CH-8803 Rüschlikon, Switzerland
3. Sealy
Center for Structural Biology and Molecular Biophysics, Department
of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
4. Department
of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States