1. Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
2. OMass Technologies Ltd The Schrodinger Building, Heatly Road, Oxford Science Park, OX4 4GE, Oxford, UK
3. Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
4. Department of Biology, ETH Zurich, Zurich, Switzerland
5. Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
6. School of Life Sciences, University of Nottingham, NG7 2UH, Nottingham, UK