Spatiotemporal Resolution Of Conformational Changes In Biomolecules By Combining Pulsed Electron-Electron Double Resonance Spectroscopy With Microsecond Freeze-Hyperquenching

The function of proteins is linked to their conformations that can be resolved with several high-resolution methods. However, only a few methods can provide the temporal order of intermediates and conformational changes, with each having its limitations. Here, we combine pulsed electron-electron double resonance spectroscopy with a microsecond freeze-hyperquenching setup to achieve spatiotemporal resolution in the angstrom range and lower microsecond time scale. We show that the conformational change of the C-alpha-helix in the cyclic nucleotide-binding domain of the Mesorhizobium loci potassium channel occurs within about 150 mu s and can be resolved with angstrom precision. Thus, this approach holds great promise for obtaining 4D landscapes of conformational changes in biomolecules.