1. Astbury Centre of Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K.
2. School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, U.K.
3. School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, U.K.
4. School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K.
5. Leiden Institute of Chemistry, University Leiden, Leiden 2300RA, The Netherlands