1. Biological Chemistry, Faculty of Medicine, Sir Alexander Fleming Building, Imperial College of Science, Technology and Medicine, University of London, Exhibition Road, South Kensington, London SW7 2AZ, United Kingdom; Unilever Research Colworth House, Sharnbrook, Bedford MK44 1LQ, United Kingdom; and Unilever Research Vlaardingen, Olivier van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands