1. Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjimacho, Tokushima 770-8506, Japan, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan, Department of Biology, Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan, and Physics Laboratory, Kansai Medical University, 18-89 Uyama-Higashi, Hirakata, Osaka 573-1136, Japan