Studies of phononlike low-energy excitations of protein molecules by inelastic x-ray scattering

Phys Rev Lett. 2008 Sep 26;101(13):135501. doi: 10.1103/PhysRevLett.101.135501. Epub 2008 Sep 24.


Molecular dynamics simulations and neutron scattering experiments have shown that many hydrated globular proteins exhibit a universal dynamic transition at TD = 220 K, below which the biological activity of a protein sharply diminishes. We studied the phononlike low-energy excitations of two structurally very different proteins, lysozyme and bovine serum albumin, using inelastic x-ray scattering above and below TD. We found that the excitation energies of the high-Q phonons show a marked softening above TD. This suggests that the large amplitude motions of wavelengths corresponding to this specific Q range are intimately correlated with the increase of biological activities of the proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Elasticity
  • Models, Chemical*
  • Models, Molecular
  • Muramidase / chemistry*
  • Neutron Diffraction
  • Protein Folding
  • Protein Structure, Secondary
  • Serum Albumin, Bovine / chemistry*
  • Thermodynamics
  • X-Ray Diffraction


  • Serum Albumin, Bovine
  • Muramidase