Exploring internal protein dynamics by neutron spin echo spectroscopy

The activity of proteins is often related to configuration changes that concern single atoms or amino acids or entire subdomains within the protein. The corresponding length and timescale reach from sub-Angstrom and picoseconds to nanometers and several tens of nanoseconds and beyond. We focus here on the slow motions on several ten nanosecond timescales of complete domains and show that and how these can be accessed by means of small angle neutron scattering and neutron spin-echo spectroscopy. In particular neutron spin echo spectroscopy is able to access timescales up to several hundred nanoseconds. Further insight into domain dynamics can be achieved by modelling the dynamics in comparison with the experimental data.