Identification of Binding Epitopes of a Fluorinated Compound Bound to Proteins Using H and F NMR Spectroscopy.

H/F NMR-based screening methods were applied to a human serum albumin-fleroxacin complex. Fleroxacin contains three fluorine atoms in a molecule, which is suitable as a model fluorinated compound for NMR analysis with H and F detection. The F{H} and H{H} saturation transfer difference spectra were acquired and the H/F spin-lattice relaxation rates were measured with and without any selective irradiation of protein resonance to identify the binding epitopes of fleroxacin. Because several H signals of fleroxacin resonated close to water, its precise signal intensities were unavailable. The F NMR-based screening methods successfully provide complementary information, indicating its importance in the analysis of fluorinated compounds.