1. Department of Medical Biochemistry Kurume University School of Medicine Kurume Fukuoka 830‐0011 Japan
2. Graduate School of Life Sciences Ritsumeikan University Kusatsu Shiga 525‐8577 Japan
3. Earth‐Life Science Institute Tokyo Institute of Technology Meguro Tokyo 152‐8550 Japan
4. PRESTO Japan Science and Technology Agency Kawaguchi Saitama 332‐0012 Japan