1. Isotope Science Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
2. Department of Medical and Life Science, Faculty of Pharmaceutical Science, Tokyo University of Science, 2669 Yamazaki, Noda-shi, Chiba 278-8510, Japan
3. Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan