Analysis of the spectroscopic characteristics on the binding interaction between tosufloxacin and bovine lactoferrin

The interaction between tosufloxacin (TELX) and bovine lactoferrin (BLF) in aqueous solution was analyzed by fluorescence spectroscopy and absorbance spectra. The binding parameters and energy-transfer efficiency parameters were determined and the mechanism of interaction was discussed. The effect of tosufloxacin acting on the BLF’s conformation was detected and the unfolding procedure of BLF induced by tosufloxacin was explored by “fluorescence phase diagram”. Following experimental data of fluorescence polarization values P and r, the saturation characteristic of such kind of binding reaction was observed for the first time. The interaction between tosufloxacin and BLF influenced by Ni2+ and Co2+ were also preliminarily explored in this work.