¹⁹F NMR as a tool in chemical biology

Abstract

We previously reviewed the use of 19F NMR in the broad field of chemical biology [Cobb, S. L.; Murphy, C. D. J. Fluorine Chem. 2009, 130, 132–140] and present here a summary of the literature from the last decade that has the technique as the central method of analysis. The topics covered include the synthesis of new fluorinated probes and their incorporation into macromolecules, the application of 19F NMR to monitor protein–protein interactions, protein–ligand interactions, physiologically relevant ions and in the structural analysis of proteins and nucleic acids. The continued relevance of the technique to investigate biosynthesis and biodegradation of fluorinated organic compounds is also described.

G-Quadruplexes and Their Ligands: Biophysical Methods to Unravel G-Quadruplex/Ligand Interactions

“…In the last few years, in order to obtain valuable structural information about G4/ligand complexes, Fluorine-19 ( 19 F) NMR has become a very useful tool [ 157 ]. The advantages of 19 F NMR spectroscopy include simplicity and sensitivity as well as its ability to study large complexes that cannot easily be probed by conventional NMR experiments [ 157 ]. Moreover, it has been applied to study G4 structures, due to the high sensitivity of the 19 F chemical shift to the environment [ 158 , 159 ].…”

19F NMR viewed through two different lenses: ligand-observed and protein-observed19F NMR applications for fragment-based drug discovery

“…62 These experiments have been prominently used for FBDD, and as such are extensively reviewed. 4,[16][17][18] In recent years several enabling methodologies have been developed that further the field, including creation of unique fluorinated fragment libraries, 63 broadband protocols for expanded mixtures, 64 quantitative methodology for measuring dissociation constants, 65,66 multi-dimensional NMR experiments (e.g., COSY, 67 ILOE 62 ), and screening protocols with both cellular lysates and intact cells. 68,69 Many of these advances will be highlighted here.…”

“…The influence of fluorine at the chemistry and biology interface Innovations in using organofluorine compounds at the chemistry and biology interface have continued to emerge over the last 80 years. Developments in biomedicine, including early work on anesthetics, 1 PET imaging, 2 magnetic resonance imaging, 3 nuclear magnetic resonance spectroscopy (NMR), 4 blood substitutes, 3 herbicides, 5 and FDA approved drugs, 5 support the broad utility of an atom that lacks sufficient endogenous levels in biological systems. With the highest electronegativity of all atoms, fluorine forms the strongest chemical bonds with carbon (e.g., 131 kcal mol À1 C-F bond dissociation energy for CF 4 ).…”

“…19 F NMR of small molecules (ligand-observed 19 F NMR) preceded target-based biomolecular 19 F NMR and as such is more developed. 4,[16][17][18] However, NMR applications of fluorinated proteins (proteinobserved 19 F NMR) is gaining increasing attention. 4,[19][20][21] Here we provide an update on new applications in ligand-observed and protein-observed fluorine NMR in drug discovery, with a particular focus on the emerging applications in fragment-based drug discovery (FBDD).…”

Fluorine NMR study of proline-rich sequences using fluoroprolines

“…Since the pioneering incorporation of p-fluorophenylalanine (Chaiken et al, 1973) into ribonuclease-S' analogues, dozens of 19 Flabelled amino acid analogues have been evaluated (Odar et al, 2015;Mei et al, 2020;Muttenthaler et al, 2021;Salwiczek et al, 2012). Common ways to incorporate fluorinated amino acids in peptides or proteins are (a) solid-phase chemical synthesis (Behrendt et al, 2016); (b) posttranslational addition of fluoroalkyl groups to reactive amino acid side chains (Liu et al, 2012); (c) addition of fluorinated precursors, such as fluoroindole, to bacterial culture media prior to protein overexpression (Crowley et al, 2012); and (d) using recombinantly expressed orthogonal amber codon tRNA/tRNA (transfer ribonucleic acid) synthetase pairs (Sharaf and Gronenborn, 2015;Gimenez et al, 2021;Gee et al, 2016;Kitevski-LeBlanc et al, 2012). The advantages of 19 F nuclei in biological NMR are the absence D. Sinnaeve et al: Fluorine NMR study of proline-rich sequences using fluoroprolines of background signals, high gyromagnetic ratio, 100 % natural abundance, and the sensitivity of 19 F chemical shift to the chemical environment (Rastinejad et al, 1995).…”