Abstract:

Both chloramphenicol (CHL) and sarafloxacin (SLFX) can quench the fluorescence from bovine serum albumin (BSA). The fluorescence will quench to a larger degree when the two drugs coexist. We thus studied the antagonism between SLFX and CHL using fluorescence spectroscopy. We prove that the antagonism between these drugs increases the binding stability between drug and protein. At the same time, a reduction of the free drug's concentration will reduce the effect of the drugs. Results show that the quenching mechanism of the combination for bovine serum albumin and drugs is a static procedure. The number of binding sites is 1. Based on the theory of Forster energy transfer spectroscopy, the binding distance r between drugs and bovine serum albumin was obtained. Because of the existence of antagonism between the drugs, the correlation coefficient and binding distance are reduced. Synchronous spectra were obtained, which showed the effect of this antagonismbetween the drugs on the conformation of BSA. The protein molecules are extended and their hydrophobic nature is reduced.

Key words: Fluorescence spectrum, Sarafloxacin, Chloramphenicol, Bovine serumalbumin, Antagonism