Spectral Characteristics of the Interaction Between Cefotaxime Sodium(CS) and Bovine Serum Albumin(BSA)

The binding interaction between cefotaxime sodium(CS) and bovine sserum albumin(BSA) was investigated by fluorescence spectra.Synchronous fluorescence spectra were used to study the structure change of BSA with the addition of CS.In physiological condition(pH7.4),CS led to the increasing of UV absorption and the quenching of intrinsic fluorescence of BSA.The Stern-Volmer curve shows that the quenching of CS to BSA is probably a single static quenching process.The binding sites number n and apparent binding constant K were measured at 25℃and 37℃and the effect of different ions on the binding constant of CTS-BSA was gained.The distance(r=2.56nm) between donor(BSA) and acceptor(CS) was obtained according to Froester theory of non-radiation energy transfer. The thermodynamic parameters △H,△G and △Sat different temperature were calculated,respectively,which indicated that electrostatic force played a major role in the interaction of CS with BSA.