Aromatic 19 F- 13 C TROSY: a background-free approach to probe biomolecular structure, function, and dynamics

Atomic-level information about the structure and dynamics of biomolecules is critical for an understanding of their function. Nuclear magnetic resonance (NMR) spectroscopy provides unique insights into the dynamic nature of biomolecules and their interactions, capturing transient conformers and their features. However, relaxation-induced line broadening and signal overlap make it challenging to apply NMR spectroscopy to large biological systems. Here we took advantage of the high sensitivity and broad chemical shift range of 19F nuclei and leveraged the remarkable relaxation properties of the aromatic 19F-13C spin pair to disperse 19F resonances in a two-dimensional transverse relaxation-optimized spectroscopy spectrum. We demonstrate the application of 19F-13C transverse relaxation-optimized spectroscopy to investigate proteins and nucleic acids. This experiment expands the scope of 19F NMR in the study of the structure, dynamics, and function of large and complex biological systems and provides a powerful background-free NMR probe.