1. Department of Chemistry School of ScienceThe University of Tokyo Hongo, Bunkyo-ku Tokyo 113-0033 Japan
2. Department of Natural Science Graduate School of Advanced Technology and ScienceTokushima University 2-1 Minami-jousanjima Tokushima 770-8506 Japan
3. Department of Biochemistry & Cell BiologyNational Institute of Infectious Diseases 1-23-1 Toyama, Shinjuku-ku Tokyo 162-8640 Japan