1. Biological Chemistry, Biomedical Sciences Division, Faculty of Medicine, Imperial College, London, SW7 2AZ, United Kingdom, Medical and Molecular Genetics, GKT School of Medicine, King's College London, London SE1 9RT, United Kingdom, The Sanger Building, Department of Biochemistry, Cambridge University, Cambridge, CB2 1QW, United Kingdom, and Department of Neurodegenerative Disease, Institute of Neurology, University College London, WC1N 3BG, United Kingdom