摘要
目的:研究头孢丙烯(CE)与牛血清白蛋白(BSA)之间的相互作用。方法:采用荧光猝灭光谱法、紫外光谱法和同步荧光光谱法,研究289、299、309 K温度下作用50 min时CE与BSA的相互作用。根据Stern-Volmer方程计算动态猝灭常数(KSV)和动态猝灭速率常数(Kq),Lineweaver-Burk方程计算静态猝灭结合常数(KLB)和紫外吸收光谱图判断猝灭类型;根据双对数方程计算结合常数(Kb)和结合位点数(n);根据热力学公式计算焓变(ΔH)熵变(ΔS)和吉布斯自由能变(ΔG);根据Hill方程计算Hill系数(nH)。结果:3个温度下的BSA荧光强度随着CE浓度升高而有规律地降低;KSV、Kq、KLB、Kb、n和nH均随着温度升高而降低;ΔG<0,ΔH<0,ΔS<0;n约等于1;nH小于1。结论:CE对BSA荧光产生静态猝灭,二者间具有一定的结合作用;其反应是一个自发的放热过程,主要结合力为氢键和范德华力,结合位点主要位于亚螺旋域ⅡA;CE对结合反应产生负协同作用,对BSA构象不产生影响;结合位点更接近于酪氨酸。
OBJECTIVE：To study the interaction of cefprozil（CE）with bovine serum albumine（BSA）. METHODS：Under the temperatures of 289,299 and 309 K,the interaction of CE with BSA for 50 min had been studied by fluorescence quenching,UV spectrometry and synchronous fluorescence spectroscopy. Quenching constant（KSV）and speed constant（Kq）were calculated by Stern-Volmer equation. Static quenching constant（KLB）was obtained by Lineweaver-Burk equation,and UV spectrogram was used to determine the type of quenching. Double logarithmic equation was used to calculate the binding constants（Kb）and the number of binding site（n）. Thermodynamic equation was used to obtain ΔH,ΔS,ΔG. Hill＇s coefficients（nH）was obtained by Hill equation. RESULTS：At three different temperatures,with CE concentration increasing,fluorescence intensity of BSA decreased regularly. The value of KSV,Kq,KLB,Kband n and nHdecreased with the temperature increasing. ΔH,ΔS and ΔG were lower than 0. The numbers of binding sites were approximately equal to 1 and nH〈1. CONCLUSIONS：CE statically quench the fluorescence of BSA,and the binding of them have been found to certain extent. The process of binding is spontaneous exothermic process. The main binding forces include Hydrogen bonds and Van der Waals forces,and primary binding site for CE is located at sub-domain ⅡA of BSA. There was some negative cooperative effect. CE would not affect the conformation of BSA. The binding site of CE and BSA is near by tyrosine residue.
出处
《中国药房》
CAS
北大核心
2015年第31期4360-4363,共4页
China Pharmacy
基金
云南省教育厅科学研究基金立项项目(No.2015C-090Y)
关键词
头孢丙烯
牛血清白蛋白
荧光猝灭光谱法
紫外光谱法
同步荧光光谱
Cefprozil
Bovine serum albumin
Fluorescence quenching spectroscopy
UV spectrometry
Synchronous fluorescence spectroscopy
作者简介
讲师，硕士。研究方向：药物化学、分子发光理论与应用。电话：0874—8998658。E—mail：m18983703680@163．com
