伊文思蓝作荧光探针研究牛血清白蛋白与红霉素之间的竞争反应

COMPETITIVE REACTION BETWEEN BOVINE SERUM ALBUMIN AND ERYTHROMYCIN WITH EVANS BLUE AS FLUORESCENT PROBE BY FLUORESCENCE SPECTROSCOPY

用伊文思蓝(EB,Evans blue)作荧光探针研究了红霉素(erythromycin,EM)对牛血清白蛋白(BSA,bo-vine serum albumin)的竞争反应。根据Stern-Volmer方程研究了荧光猝灭的类型及机理,伊文思蓝与牛血清白蛋白作用,使牛血清白蛋白荧光发生静态猝灭,即伊文思蓝和牛血清白蛋白形成了一种稳定的复合物。伊文思蓝与牛血清白蛋白的结合常数KBSA-EB=1.122×106L/mol,结合点数n=0.9935。当加入红霉素后,牛血清白蛋白的相对荧光强度恢复,表明红霉素与牛血清白蛋白发生了竞争反应,探讨了相关机理,得到了伊文思蓝与红霉素的结合常数KEB-EM=1.950×104L/mol。

The competitive interaction between erythromycin and bovine serum albumin （BSA） was studied with Evans blue （EB） as fluorescence probe by the fluorescence spectroscopy. Fluorescence quenching was occurred between the bovine serum albumin and Evans blue. The static fluorescence quenching process was confirmed based on the Stern-Volmer plot. The binding constant KBSA-EB was 1.122×10^6 L/mol and the number of binding sites n was 0.9935. The relative fluorescence intensity of BSA was recovered gradually with an increasing the concentration of erythromycin. This indicated there was a competitive interaction between erythromycin and EB for BSA, and the interaction mechanism was studied. The binding constant of EB with erythromycin KEB-EMwas 1.950×10^4 L/mol.