1. Division of Structural Cell Biology, Nara Institute of Science and Technology, 8916–5 Takayama, Ikoma, Nara, 630–01 Japan,
2. JBC Inc., Fukue, Kaizu, Gifu, 503‐06, Japan,
3. Medical and Biological Laboratories Co. Ltd., Fukue, Kaizu, Gifu, 503‐06, Japan