Myoglobin in crowded solutions: structure and diffusion

Abstract

Abstract We present a neutron scattering study of the structure and diffusion of myoglobin solutions at high concentration. The protein–protein structure factor was determined by small angle neutron scattering (SANS) measurements using mean spherical analysis (MSA), and the intermediate scattering function was measured by neutron spin-scho spectroscopy. We observe the cross-over between self-diffusion at high Q and collective diffusion below the structure factor maximum. The self-diffusion coefficient decreases exponentially with concentration. The collective diffusion coefficient is shown to increase at low Q due to direct interactions.