1. Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
2. Department of Chemistry, Nanoscience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
3. Department of Physics, Nanoscience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
4. Physical Bioscience Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA.
5. Stanford Nanocharacterization Laboratory, Stanford University, Stanford, CA 94305, USA.
6. Catalysis Research Center, Hokkaido University, Sapporo, Japan.