Fractal globule as an molecular machine

V. A. Avetisov 12, V. A. Ivanov 3, D. A. Meshkov 1, S. K. Nechaev 45

JETP Letters 98, 4 (2013) 242-246

The relaxation of an elastic network, constructed by a contact map of a fractal (crumpled) polymer globule is investigated. We found that: i) the slowest mode of the network is separated from the rest of the spectrum by a wide gap, and ii) the network quickly relaxes to a low--dimensional (one-dimensional, in our demonstration) manifold spanned by slowest degrees of freedom with a large basin of attraction, and then slowly approaches the equilibrium not escaping this manifold. By these dynamic properties, the fractal globule elastic network is similar to real biological molecular machines, like myosin. We have demonstrated that unfolding of a fractal globule can be described as a cascade of equilibrium phase transitions in a hierarchical system. Unfolding manifests itself in a sequential loss of stability of hierarchical levels with the temperature change.

  • 1 : The Semenov Institute of Chemical Physics
    Russian Academy of Sciences
  • 2 : National Research University Higher School of Economics
    National Research University Higher School of Economics
  • 3 : Moscow State University
    Moscow State University
  • 4 : Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS)
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 5 : P. N. Lebedev Physical Institute
    Russian Academy of Science