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This content will become publicly available on November 23, 2016

Title: The dynamics of single protein molecules is non-equilibrium and self-similar over thirteen decades in time

Here, internal motions of proteins are essential to their function. The time dependence of protein structural fluctuations is highly complex, manifesting subdiffusive, non-exponential behavior with effective relaxation times existing over many decades in time, from ps up to ~102s (refs 1-4). Here, using molecular dynamics simulations, we show that, on timescales from 10–12 to 10–5s, motions in single proteins are self-similar, non-equilibrium and exhibit ageing. The characteristic relaxation time for a distance fluctuation, such as inter-domain motion, is observation-time-dependent, increasing in a simple, power-law fashion, arising from the fractal nature of the topology and geometry of the energy landscape explored. Diffusion over the energy landscape follows a non-ergodic continuous time random walk. Comparison with single-molecule experiments suggests that the non-equilibrium self-similar dynamical behavior persists up to timescales approaching the in vivo lifespan of individual protein molecules.
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  2. Shanghai Jiao Tong Univ., Shanghai (China)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Rhein-Main Univ. of Applied Sciences, Weisbaden (Germany)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nature Physics
Additional Journal Information:
Journal Volume: 12; Journal Issue: 2; Journal ID: ISSN 1745-2473
Nature Publishing Group (NPG)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
Country of Publication:
United States