1. Biomacromolecule Research Team, RIKEN Center for Sustainable Resource Science, Wako-shi, Saitama 351-0198, Japan
2. Institute for Advanced Biosciences, Keio University, Tsuruoka-shi, Yamagata 997-0017, Japan.
3. Department of Material Chemistry, Kyoto University, Kyoto-shi, Kyoto 606-8501, Japan