1. Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
2. Laboratory of Bioorganic Chemistry, Graduate School of Information Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
3. Department of Applied Chemistry, Faculty of Engineering, Aichi Institute of Technology, 1247 Yachigusa, Yakusa, Toyota 470-0392, Japan
4. School of Public Health, University of California, Berkeley, California 94720