Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China; Department of Cell and Developmental Biology & Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, United States
Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China; Shanghai National Center for Applied Mathematics (SJTU Center), Shanghai Jiao Tong University, Shanghai, China
Banghao Wu
Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China; School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
Yang Tan
Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China; Shanghai National Center for Applied Mathematics (SJTU Center), Shanghai Jiao Tong University, Shanghai, China
Juan Huang
Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China; School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
Madhusudan Tyagi
Department of Materials Science and Engineering, University of Maryland, College Park, United States; NIST Center for Neutron Research, National Institute of Standards and Technology (NIST), Gaithersburg, United States
Victoria García Sakai
ISIS Pulsed Neutron and Muon Source, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot, United Kingdom
Takeshi Yamada
Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Ibaraki, Japan
Hugh O'Neill
Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, United States
Qiu Zhang
Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, United States
The protein dynamical transition at ~200 K, where the biomolecule transforms from a harmonic, non-functional form to an anharmonic, functional state, has been thought to be slaved to the thermal activation of dynamics in its surface hydration water. Here, by selectively probing the dynamics of protein and hydration water using elastic neutron scattering and isotopic labeling, we found that the onset of anharmonicity in the two components around 200 K is decoupled. The one in protein is an intrinsic transition, whose characteristic temperature is independent of the instrumental resolution time, but varies with the biomolecular structure and the amount of hydration, while the one of water is merely a resolution effect.
