1. a Graduate School of Science and Engineering, Saitama University, Shimo-Ohkubo 255, Urawa-shi, Saitama 338, Japan
2. b Biochemical Systems Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan
3. c Biochemical Systems Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan
4. d Department of Mechanical Systems Engineering, Utsunomiya University, Ishii-cho 2753, Utsunomiya-shi, Tochigi 321, Japan
5. e Biochemical Systems Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan
6. f Biochemical Systems Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan