荧光、同步荧光、三维荧光和圆二色谱法研究头孢吡肟盐酸盐与牛血清白蛋白的相互作用

摘要

药物和蛋白质相互作用的研究有助于深入理解生物药剂学、药代动力学和药物毒性以及蛋白质结构和功能的关系,尽管利用计算机模拟分子对接的方法研究了头孢吡肟盐酸盐和牛血清白蛋白的相互作用,但是还没有利用荧光、同步荧光、三维荧光和圆二色谱研究两者相互作用的报告.本论文利用分子光谱调查了不同pH条件下头孢吡肟盐酸盐和牛血清白蛋白的相互作用.计算获得的猝灭速率常数和结合常数证明该猝灭属于静态猝灭,结合力中等,同时利用光谱法也研究了头孢吡肟盐酸盐对牛血清白蛋白构象的影响.此外,也调查了pH对头孢吡肟盐酸盐和牛血清白蛋白的相互作用,结果表明在pH 7.4时的结合力最强.牛血清白蛋白的变性会减少头孢吡肟盐酸盐和牛血清白蛋白的结合力.此外,考察了金属离子对头孢吡肟盐酸盐和牛血清白蛋白结合常数的影响.%The investigation on the binding mode between drug and protein is extremely important to understand biopharmaceutics,pharmacokinetics and toxicity of the drug as well as the relationship of structure and function of the protein.It is well proved that biological activity is a function of the chemical structure or structural properties.There is a study on the interaction of cefepime hydrochloride with serum albumin using in-silico molecular docking.But up to date,there is hardly any interaction investigation of cefepime hydrochloride with serum albumin utilizing by fluorescence,synchronous fluorescence,three-dimensional fluorescence and circular dichroism.In this study,the interaction of cefepime hydrochloride with bovine serum albumin in aqueous solution has been investigated by molecular spectroscopy under different pH conditions.The quenching rate constant and binding constant calculated at pH 7.4 indicated the static quenching mechanism and medium binding force.The effect of cefepime hydrochloride on the conformation of bovine serum albumin was analyzed using fluorescence,synchronous fluorescence,three-dimensional fluorescence and circular dichroism.In addition,influence of pH on the binding of cefepime hydrochloride to bovine serum albumin was investigated and the binding ability of the drug to bovine serum albumin deceased under other pH conditions (pH 1.9,3.5,and 9.0) as compared with that at pH 7.4.As compared with the binding ability of cefepime hydrochloride to native bovine serum albumin,that of cefepime hydrochloride to denatured bovine serum albumin deceases dramatically.Furthermore,the effect of metal ions on the binding constant of cefepime hydrochloride with bovine serum albumin was investigated.