Dynamical heterogeneity of protein dynamics studied by elastic incoherent neutron scattering and molecular simulations

The dynamical heterogeneity of a globular soluble protein was studied by elastic incoherent neutron scattering and molecular simulations. The q-dependence of the elastic incoherent neutron scattering shows a non-Gaussianity, a deviation from Gaussian approximation. We determined that the dynamical heterogeneity explains the non-Gaussianity, although the anharmonicity is also plausible origin. Molecular dynamics simulations confirmed that the non-Gaussianity is mainly due to the dynamical heterogeneity at a lower energy resolution, Δω ∼ 1 meV. On the other hand, the contribution from the anharmonicities to the non-Gaussianity became substantial at a higher resolution, Δω ∼ 10 μeV. Regardless, the dynamical heterogeneity is the dominant factor for the non-Gaussianity.