1. Department of Chemical Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
2. Present address: Division of Molecular Science, Faculty of Science and Technology Gunma University 1-5-1 Tenjin-cho Kiryu Gunma 376-8515 Japan
3. Present address: Biomacromolecules Research Team RIKEN Center for Sustainable Resource Science 2-1 Hirosawa Wako Saitama 351-0198 Japan
4. Department of Chemical Science and Engineering Tokyo Institute of Technology 2-12-1, Ookayama Meguro-ku Tokyo 152-8552 Japan