1. Division of Applied Life Science (BK 21), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea
2. Division of Electron Microscopic Research, Korea Basic Science Institute, 52 Eoeun-dong, Daejeon 305-333, Republic of Korea
3. Department of Life Science, Chung-Ang University, Seoul 156-756, Republic of Korea