1. Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, United States
2. Department of Diseases of the Developing World, GlaxoSmithKline, Parque Tecnológico de Madrid, Calle de Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
3. Medicines Discovery Institute, Cardiff University, Cardiff CF10 3AT, United Kingdom
4. VA Tennessee Valley Healthcare System, Nashville, Tennessee 37212, United States