title: The impact of high hydrostatic pressure on structure and dynamics of β-lactoglobulin.
abstract: METHODS
  Combining small-angle X-ray and neutron scattering measurements with inelastic neutron scattering experiments, we investigated the impact of high hydrostatic pressure on the structure and dynamics of β-lactoglobulin (βLG) in aqueous solution.
  
  
  BACKGROUND
  βLG is a relatively small protein, which is predominantly dimeric in physiological conditions, but dissociates to monomer below about pH3.
  
  
  RESULTS
  High-pressure structural results show that the dimer-monomer equilibrium, as well as the protein-protein interactions, are only slightly perturbed by pressure, and βLG unfolding is observed above a threshold value of 3000bar. In the same range of pressure, dynamical results put in evidence a slowing down of the protein dynamics in the picosecond timescale and a loss of rigidity of the βLG structure. This dynamical behavior can be related to the onset of unfolding processes, probably promoted from water penetration in the hydrophobic cavity.
  
  
  CONCLUSIONS
  Results suggest that density and compressibility of water molecules in contact with the protein are key parameters to regulate the protein flexibility.
authors.affiliation: CNR-IOM, c/o Institut Laue-Langevin, Grenoble, France. russo@ill.fr
authors.forename: Daniela
authors.initials: D
authors.lastname: Russo
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Ortore
authors.forename: Francesco
authors.initials: F
authors.lastname: Spinozzi
authors.forename: Paolo
authors.initials: P
authors.lastname: Mariani
authors.forename: Camille
authors.initials: C
authors.lastname: Loupiac
authors.forename: Burkhard
authors.initials: B
authors.lastname: Annighofer
authors.forename: Alessandro
authors.initials: A
authors.lastname: Paciaroni
mesh_terms: D006874:Hydrostatic Pressure; D007782:Lactoglobulins / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D007782:Lactoglobulins
keywords: Hydrostatic pressure; Neutron scattering; Protein dynamics; Protein folding; Small angle X-ray and neutron scattering