Measurement of Angstrom to Nanometer Molecular Distances with ¹⁹ F Nuclear Spins by EPR/ENDOR Spectroscopy.

ABSTRACT: Spectroscopic and biophysical methods for structural determination at atomic resolution are fundamental in studies of biological function. Here we introduce an approach to measure molecular distances in bio-macromolecules using ¹⁹ F nuclear spins and nitroxide radicals in combination with high-frequency (94?GHz/3.4?T) electron-nuclear double resonance (ENDOR). The small size and large gyromagnetic ratio of the ¹⁹ F label enables to access distances up to about 1.5?nm with an accuracy of 0.1-1?Å. The experiment is not limited by the size of the bio-macromolecule. Performance is illustrated on synthesized fluorinated model compounds as well as spin-labelled RNA duplexes. The results demonstrate that our simple but strategic spin-labelling procedure combined with state-of-the-art spectroscopy accesses a distance range crucial to elucidate active sites of nucleic acids or proteins in the solution state.

SUBMITTER: Meyer A 

PROVIDER: S-EPMC6973229 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature