1. National Center for Magnetic Resonance in WuhanKey Laboratory of Magnetic Resonance in Biological SystemsState Key Laboratory of Magnetic Resonance andAtomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of Sciences Wuhan 430071 P. R. China
2. University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. College of Life Science & TechnologyHuazhong University of Science and Technology Wuhan 430071 P. R. China
4. Drug Discovery and Design CenterCAS Key Laboratory of Receptor ResearchState Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of Sciences Shanghai 201203 P. R. China