Spatiotemporal Resolution of Conformational Changes in Biomolecules by Combining Pulsed Electron-Electron Double Resonance Spectroscopy with Microsecond Freeze-Hyperquenching

J Am Chem Soc. 2021 May 12;143(18):6981-6989. doi: 10.1021/jacs.1c01081. Epub 2021 Apr 27.

Abstract

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 Cα-helix in the cyclic nucleotide-binding domain of the Mesorhizobium loti potassium channel occurs within about 150 μs and can be resolved with angstrom precision. Thus, this approach holds great promise for obtaining 4D landscapes of conformational changes in biomolecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrons*
  • Freezing*
  • Mesorhizobium / chemistry*
  • Models, Molecular
  • Potassium Channels / chemistry
  • Potassium Channels / metabolism*
  • Protein Conformation
  • Spectrum Analysis
  • Time Factors

Substances

  • Potassium Channels

Supplementary concepts

  • Mesorhizobium loti