荧光光谱在研究氯霉素与沙拉沙星间拮抗作用中的应用

氯霉素(CHL)和沙拉沙星(SLFX)均能够猝灭牛血清白蛋白(BSA)的荧光. 当两种药物共存时使BSA荧光进一步猝灭, 据此利用荧光光谱法研究了氟喹诺酮类药物SLFX与CHL间相互作用. 结果表明: 两种药物间存在拮抗作用, 使药物与蛋白的结合稳定性增加, 致使能够转运到作用部位产生药理效应的游离型药物含量减少, 造成药效降低; 药物对蛋白荧光的猝灭属于静态猝灭; 药物与蛋白结合位点数约为1. 根据Forster非辐射能量转移理论, 确定了药物与蛋白之间的结合距离r, 药物间拮抗作用的存在使r值降低, 结合距离减小. 同步荧光光谱研究表明, 药物间的拮抗作用对蛋白质构象产生影响, 使蛋白质分子伸展, 疏水性降低.

Application of Fluorescence Spectroscopy to a Study on the Antagonism between Chloramphenicol and Sarafloxacin

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.