Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.|Department of Physics and Randall Division of Cell and Molecular Biophysics, Kings College London, London, UK.