title: Protein dynamical transition at 110 K.
abstract: Proteins are known to undergo a dynamical transition at around 200 K but the underlying mechanism, physical origin, and relationship to water are controversial. Here we report an observation of a protein dynamical transition as low as 110 K. This unexpected protein dynamical transition precisely correlated with the cryogenic phase transition of water from a high-density amorphous to a low-density amorphous state. The results suggest that the cryogenic protein dynamical transition might be directly related to the two liquid forms of water proposed at cryogenic temperatures.
authors.affiliation: Cornell High Energy Synchrotron Source, Laboratory of Atomic and Solid State Physics, and Department of Physics, Cornell University, Ithaca, NY 14853, USA. ck243@cornell.edu
authors.forename: Chae Un
authors.initials: CU
authors.lastname: Kim
authors.forename: Mark W
authors.initials: MW
authors.lastname: Tate
authors.forename: Sol M
authors.initials: SM
authors.lastname: Gruner
mesh_terms: D003080:Cold Temperature; D018360:Crystallography, X-Ray; D010940:Plant Proteins / Q000737:chemistry*; D011312:Pressure; D011487:Protein Conformation; D014867:Water / Q000737:chemistry
chemical_list: D010940:Plant Proteins; D014867:Water; C003427:thaumatin protein, plant