1. Department of Chemistry, Institute of Basic Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, Korea, Center for Computational Biology and Bioinformatics, Korea Institute of Science and Technology Information, 52, Eoeun-dong, Yuseong, Daejeon 305-806, Korea, and Department of Applied Chemistry, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi 730-701, Korea