1. Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
2. GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
3. GlaxoSmithKline, 200 Cambridge Park Drive, Cambridge, Massachusetts 02140, United States