Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.|Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.|Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.|Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.