Before revision:  MD provided a wealth of information about the timescale of the different motional contributions to the overall dynamics of the spin label . These data were validated by multi-frequency continuous-wave electron paramagnetic resonance (EPR) measurements, that relying on the frequency dependence of the fast and slow motions of the spin probe were used to distinguish the fast internal motion of the spin label from slow protein tumbling.
After revision:  MD provided a wealth of information about the timescale of the different motional contributions to the overall dynamics of the spin label in space was found due to the large exposure of the activation loop to the solvent water. A hydrodynamic approach was employed to determine the rotational protein tumbling, while the internal motion of the spin label from slow protein tumbling.