奥硝唑对映体与牛血清白蛋白的相互作用研究

利用荧光光谱法分别研究了S-奥硝唑(S-ONZ)和R-奥硝唑(R-ONZ)与牛血清白蛋白(BSA)相互作用机制。结果表明S-ONZ和R-ONZ均能猝灭BSA的荧光,属于静态猝灭。根据Stern-Volmer方程和结合反应方程式分别计算出了反映药物与BSA作用机制的参数:猝灭常数KSV,结合常数KA,结合位点数n。由求得的热力学参数(ΔH、ΔS和ΔG)判断了药物与BSA之间作用力主要类型为静电作用。此外,本文同时考察了溶液pH值和异丙醇对药物和BSA之间作用力类型及作用强度的影响。实验方法简便、快速,实验结果初步阐明药物与BSA作用机制,有助于解释奥硝唑不同对映体的药效差异。

Study on the Interaction Between Ornidazole Enantiomers and Bovine Serum Albumin

The mechanism of interaction between bovine serum albumin（BSA） and S-ornidazole（S-ONZ） as well as R-ornidazole （R-ONZ） were investigated by fluorescence spectroscopy.The fluorescence of BSA was quenched in the presence of S-ONZ（or R-ONZ）.Based on the Stern-Volmer equation,the quenching constants（KSV） were obtained.The association constants （KA） and the number of binding sites （n） were also obtained by fluorescence quenching method.The thermodynamic parameters,enthalpy change（ΔH）,entropy change （ΔS）,and free energy change （ΔG） were calculated and used to evaluate the mainly binding type of BSA with ornidazole enantiomers.The effects of pH and isopropanol on the drug-BSA system were examined.This method is simple and rapid.The results of this study are useful for clarifying the different curative effect of two enantiomers.