1. Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
2. Molecular Medical Science Institute, Otsuka Pharmaceutical Co. Ltd., 463-10 Kagasuno, Kawauchi, Tokushima 771-0192, Japan
3. Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan