Development of ¹H{¹⁹F} saturation transfer difference experiments for detection of a fluorinated compound bound to...

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.