Fluorine-19 NMR of integral membrane proteins illustrated with studies of GPCRs

Fluorine-19 is a spin-1/2 NMR isotope with high sensitivity and large chemical shift dispersion, which makes it attractive for high resolution NMR spectroscopy in solution. For studies of membrane proteins it is further of interest that F-19 is rarely found in biological materials, which enables observation of extrinsic F-19 labels with minimal interference from background signals. Today, after a period with rather limited use of F-19 NMR in structural biology, we witness renewed interest in this technology for studies of complex supramolecular systems. Here we report on recent F-19 NMR studies with the G protein-coupled receptor family of membrane proteins.