1. Institute of Physical and Theoretical Chemistry, Cluster of Excellence Frankfurt “Macromolecular Complexes”, Center for Membrane Proteomics, Goethe University, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
2. Beckman Institute, California Institute of Technology, Pasadena, California 91125, United States
3. J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
4. Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, United Kingdom