Journal of Biological Physics

, 33:371

A Physical Picture of Protein Dynamics and Conformational Changes


    • Physik-Department E17Technische Universität München
  • Klaus Achterhold
    • Physik-Department E17Technische Universität München
  • Simonetta Croci
    • Physik-Department E17Technische Universität München
    • Sezione di Fisica, Dipartimento di Sanità PubblicaUniversità di Parma
  • Marius Schmidt
    • Physik-Department E17Technische Universität München
    • Department of PhysicsUniversity of Wisconsin-Milwaukee
Original Paper

DOI: 10.1007/s10867-008-9102-3

Cite this article as:
Parak, F.G., Achterhold, K., Croci, S. et al. J Biol Phys (2007) 33: 371. doi:10.1007/s10867-008-9102-3


A physical model is reviewed which explains different aspects of protein dynamics consistently. At low temperatures, the molecules are frozen in conformational substates. Their average energy is 3/2RT. Solid-state vibrations occur on a time scale of femtoseconds to nanoseconds. Above a characteristic temperature, often called the dynamical transition temperature, slow modes of motions can be observed occurring on a time scale between about 140 and 1 ns. These motions are overdamped, quasidiffusive, and involve collective motions of segments of the size of an α-helix. Molecules performing these types of motion are in the “flexible state”. This state is reached by thermal activation. It is shown that these motions are essential for conformational relaxation. Based on this picture, a new approach is proposed to understand conformational changes. It connects structural fluctuations and conformational transitions.


Protein dynamicsConformational relaxationMössbauer effectMyoglobin

Copyright information

© Springer Science+Business Media B.V. 2008