1. Department of Medicinal Chemistry, Center for Frontier Research in Medicinal Science, 21st Century COE Program, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8412, Japan
2. Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064
3. Molecular Structural Biology Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan