1. School of Biology and Chemistry, Biomedical Sciences Research Complex, University of St Andrews, North Haugh, KY16 9ST, UK
2. Biophysical Sciences Institute, School of Biological and Biomedical Sciences and Department of Chemistry, University of Durham University Science Laboratories, South Road, Durham DH1 3LE, UK
3. School of Medicine and Health, Durham University, Queen's Campus, Stockton-on-Tees TS17 6BH, UK