1. Department of NeurochemistryTohoku University Graduate School of MedicineAoba‐Ku Sendai980‐8575 Japan
2. Department of Medicinal ChemistryKyoto Pharmaceutical UniversityYamashina‐Ku Kyoto607‐8412 Japan
3. R&D Center, Protein Wave CoNara631‐0006 Japan
4. Institute for Protein Research, Osaka UniversitySuita Osaka565‐0871 Japan