Rational design of 19F NMR labelling sites to probe protein structure and interactions

Abstract

Proteins are investigated in increasingly more complex biological systems, where 19F NMR is proving highly advantageous due to its high gyromagnetic ratio and background-free spectra. Its application has, however, been hindered by limited chemical shift dispersions and an incomprehensive relationship between chemical shifts and protein structure. Here, we exploit the sensitivity of 19F chemical shifts to ring currents by designing labels with direct contact to a native or engineered aromatic ring. Fifty protein variants predicted by AlphaFold and molecular dynamics simulations show 80–90% success rates and direct correlations of their experimental chemical shifts with the magnitude of the en..