1. Department of Oral Biochemistry, Dental Science Research Institute, The second Stage of Brain Korea 21 for Dental School, Chonnam National University, Gwangju 500-757, Republic of Korea, Korea Basic Science Institute, Gwangju 500-757, Republic of Korea, Bio-Therapy Human Resources Center, College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, Republic of Korea, and School of Life Science and Biotechnology, Kyungpook National University, Daegu 702-701, Republic of Korea