摘要
利用荧光光谱、紫外-可见吸收光谱法结合分子对接法,研究了水溶液中1-羟基芘（1-OHP）与过氧化氢酶（CAT）的相互作用.结果表明,1-OHP对CAT的内源荧光有较强的猝灭作用,且静态猝灭是引起CAT荧光猝灭的主要原因.1-OHP能与CAT形成1∶1复合物,在290 K下其结合常数为2.96×10^5L/mol.热力学分析结果表明,1-OHP与CAT结合的作用力主要为氢键和范德华力.根据Forster的非辐射能量转移理论计算得二者结合距离为3.48 nm.同步荧光和紫外-可见吸收光谱结果表明,1-OHP-CAT复合物的形成可使CAT构象发生变化,且高浓度的1-OHP对CAT的活性有明显的抑制作用.利用分子对接法预测了1-OHP在CAT上的最优结合位点和详细的结合信息,所得结果与实验相符.
The interactions between 1-hydroxypyrene （1-OHP） and catalase （CAT） were investigated by fluorescence, UV visible absorption （UV-Vis） spectra and molecular docking methods in aqueous solutions. The experimental results showed that the intrinsic fluorescence of CAT was quenched by the addition of 1-OHP through a static quenching mechanism. 1-OHP can bind with CAT to form 1 ： 1 complex, with a binding constant of 2. 96×10^5 L/mol at 290 K. The result of thermodynamic analysis indicated that hydrogen bonds and van der Waals＇ force were the dominant intermolecular forces in stabilizing the complex. Based on the Forster＇ s non-radiation energy transfer theory, the binding distance between 1-OHP and CAT was determined to be 3.48 nm. The synchronous fluorescence and UV-Vis absorption spectral results showed that the formation of 1-OHP-CAT complex can induce some conformation changes of CAT. And in the presence of high concen- trations of 1-OHP, the CAT activity can he inhibited obviously. Molecular docking was further employed to seek the optimum binding site of 1-OHP in CAT, and get the detailed binding information, which is identical to the experiment results. This work contributes to understand the interaction mechanism between 1-OHP and CAT at the molecular level, and provides important insights to study the toxicity mechanism of PAHs and their metabolites on antioxidant enzyme system in organisms.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第12期2394-2401,共8页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21075102
21177102)
中央高校基本科研业务费专项资金(批准号:2013121052)资助~~
关键词
1-羟基芘
过氧化氢酶
光谱法
分子对接
构象变化
1-Hydroxypyrene
Catalase
Spectroscopic method
Molecular docking
Conformation change
