[Study on the interaction between sparfloxacin and serum albumins by fluorescence]

The binding reaction between sparfloxacion (SPFX) and bovine serum albumin (BSA) or chicken egg albumin (CEA) in aqueous was studied using fluorescence and absorption spectra. Their binding constants are KCEA = 8.29 x 10(6) and KBSA = 4.41 x 10(7), and the binding sites are nCEA = 0.558, nBSA = 0.793 respectively. The action distances (RCEA = 1.99 nm, RBSA = 2.09 nm) and energy transfer efficiencies (ECEA = 0.766, EBSA = 0.714) between donor-acceptor and SPFX were obtained by Förster's nonradiative energy transfer mechanism. The experiment demonstrated that the higher the temperature is, the lower the slopes of quenching curves of BSA and CEA are in presence of different amounts of SPFX. It is confirmed that the combination for SPFX with BSA or CEA is a single static quenching process, their interaction may be interpreted with energy transfer mechanism. Through binding reaction of the two albumins with SPFX, the biological effects and action mechanism of SPFX with albumins in vivo were discussed.