The 1H{19F} saturation transfer difference (STD) experiment presented here incorporates the WATERGATE W5 sequence to observe protein-ligand interactions in a human serum albumin (HSA)-fleroxacin complex. In conventional STD experiments, 1H of proteins are first saturated, and the ligands bound to these proteins are then observed. The method proposed here reverses this process: fluorine atoms in fleroxacin are selectively saturated, and saturation transfer then occurs to protons of fleroxacin as well as to those of HSA. The combined use of the present 1H{19F} STD and conventional STD methods is expected to provide better insight in the analysis of the role of fluorine atoms in a fluorinated compound.
Keywords: 19F NMR; Fluorinated compounds; NMR-based screening; STD; WATERGATE W5 sequence.
© 2022. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry.