1. Laboratory of Biochemistry, Laboratories of Applied Microbiology, Suntory Research Center, Shimamoto-cho, Mishima-gun, Osaka 618, Japan
2. Suntory Institute of Bioorganic Research, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618, Japan
3. Department of Clinical Science, Kyoto University Faculty of Medicine, Sakyo-ku, Kyoto 606, Japan