Protein Dynamical Heterogeneity Derived from Neutron Incoherent Elastic Scattering

Abstract

Dynamical heterogeneity of a protein, staphylococcal nuclease, was studied using incoherent elastic neutron scattering at various temperatures. The elastic scattering intensity profile at low q region can be approximated with a Gaussian function, while the deviation from the function becomes remarkable at higher q-region. We analyzed the non-Gaussianity in terms of protein dynamical heterogeneity. Three typical distribution, Gaussian, bimodal, and exponential distribution, were applied to the data analysis to obtain the average mean square displacement and the width of distribution. The analysis showed that the non-Gaussianity comes partly from dynamical heterogeneity and that a bimodal distribution is adequate for quantitative analysis.