Insights into the Structure and Dynamics of Proteins from F Solution NMR Spectroscopy.

F NMR spectroscopy has recently witnessed a resurgence as an attractive analytical tool for the study of the structure and dynamics of biomolecules in vitro and in cells, despite reports of its applications in biomolecular NMR since the 1970s. The high gyromagnetic ratio, large chemical shift dispersion, and complete absence of the spin 1/2 F nucleus from biomolecules results in background-free, high-resolution F NMR spectra. The introduction of F probes in a few selected locations in biomolecules reduces spectral crowding despite its increased line width in comparison to typical H NMR line widths and allows rapid site-specific measurements from simple 1D spectra alone. The design and synthesis of novel F probes with reduced line widths and increased chemical shift sensitivity to the surrounding environment, together with advances in labeling techniques, NMR methodology, and hardware, have overcome several drawbacks of F NMR spectroscopy. The increased interest and widespread use of F NMR spectroscopy of biomolecules is gradually establishing it as a sensitive and high-resolution probe of biomolecular structure and dynamics, supplementing traditional C/N-based methods. This Review focuses on the advances in F solution NMR spectroscopy of proteins in the past 5 years, with an emphasis on novel F tags and labeling techniques, NMR experiments to probe protein structure and conformational dynamics in vitro, and in-cell NMR applications.