1. Randall Centre for Cell and Molecular Biophysics, King’s College London, London SE1 1UL, UK
2. MRC Biomedical NMR Centre, The Francis Crick Institute, London NW1 1AT, UK
3. Centre for Biomolecular Spectroscopy, King’s College London, London SE1 1UL, UK
4. Department of Chemistry, King’s College London, London SE1 1DB, UK