1. Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801; Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht Strasse 74, 20359 Hamburg, Federal Republic of Germany; Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; Department of Biochemistry and Molecular Biology, The Chicago Medical School, North Chicago, Illinois 60064; Department of...