1. Biological Chemistry, Biomedical Sciences Division, Imperial College of Science, Technology, and Medicine, University of London, Sir Alexander Fleming Building, South Kensington, London SW7 2AY, U.K., Centre for Research in Biomedicine, Faculty of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, U.K., and Bionomix Ltd., Canada House, 272 Field End Road, Middlesex HA4 9NA, U.K.