1. Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea
2. Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77005, USA
3. Department of Chemistry, Seoul National University, Seoul 151-747, Republic of Korea
4. Department of Genetic Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea