THE REACTION MECHANISM BETWEEN OFLOXACIN AND BOVINE SERUM ALBUMIN

AIM　To study the reaction mechanism between ofloxacin and bovine serum albumin (BSA) in aqueous solution. METHODS　Fluorescence spectra and microcalorimetry was used. RESULTS　The binding constant K was found to be 1.20×10⁵ L.mol^-1 and the number of binding site n was 1.20. Microcalorimetric measurements showed that the molar enthalpy change was Δ_rH_m≈0 for the reaction. The effect of ofloxacin on the conformation of BSA was analyzed using synchronous fluorescence spectrometry. The binding distance (r=2.59 nm) and transfer efficiency (E=0.38) between ofloxacin and BSA were also obtained according to the theory of Fōrster′s non-radiation energy transfer. CONCLUSION　The interaction between ofloxacin and BSA is stronger and the main binding force is hydrophobic interactions.