title: Derivation of mean-square displacements for protein dynamics from elastic incoherent neutron scattering.
abstract: The derivation of mean-square displacements from elastic incoherent neutron scattering (EINS) of proteins is examined, with the aid of experiments on camphor-bound cytochrome P450cam and complementary molecular dynamics simulations. It is shown that a q(4) correction to the elastic incoherent structure factor (where q is the scattering vector) can be simply used to reliably estimate from the experiment both the average mean-square atomic displacement, <Δr(2)> of the nonexchanged hydrogen atoms in the protein and its variance, σ(2). The molecular dynamics simulation results are in broad agreement with the experimentally derived <Δr(2)> and σ(2) derived from EINS on instruments at two different energy resolutions, corresponding to dynamics on the ∼100 ps and ∼1 ns time scales. Significant dynamical heterogeneity is found to arise from methyl-group rotations. The easy-to-apply q(4) correction extends the information extracted from elastic incoherent neutron scattering experiments and should be of wide applicability.
authors.affiliation: University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics , P.O. Box 2008, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yi
authors.forename: Yinglong
authors.initials: Y
authors.lastname: Miao
authors.forename: Jerome
authors.initials: J
authors.lastname: Baudry
authors.forename: Nitin
authors.initials: N
authors.lastname: Jain
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Smith
mesh_terms: D019475:Camphor 5-Monooxygenase / Q000737:chemistry* / Q000378:metabolism; D004548:Elasticity; D056004:Molecular Dynamics Simulation; D033363:Neutron Diffraction
chemical_list: D019475:Camphor 5-Monooxygenase