1. Department of Applied MechanicsWaseda University3‐4‐1 Okubo, Shinjuku‐kuTokyo169‐8555Japan
2. NMR FacilityDivision of Structural and Synthetic BiologyRIKEN Center for Life Science TechnologiesYokohama Campus, 1‐7‐22 C116, Suehiro‐cho, Tsurumi‐kuYokohamashi230‐0045Japan