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以 β 环糊精 (CD)为酶模型 ,将Te引入 β 环糊精中 ,成功地合成出一种新的水溶性好、活力高的谷胱甘肽过氧化物酶(GPX)小分子模拟物 2 TeCD ,并对其结构进行了表征 .采用Wilson辅酶偶联法 ,间接测定了 2 TeCD催化还原型谷胱甘肽(GSH)还原H2 O2 的GPX活力为 46 7U/ μmol,与文献报道的数据相比 ,2 TeCD的GPX活力最高 .通过考察 2 TeCD催化GSH还原H2 O2 反应的动力学 ,发现反应初速度对底物浓度的双倒数曲线为一组平行线 ,表明 2 TeCD所遵循的催化机制可能为三转移乒乓机制 .通过考察自由基捕获剂 2 ,4 二叔丁基甲基苯酚对酶促和自发反应速率的影响 ,发现 2 TeCD催化的酶促反应为非自由基机理 .通过考察酶不可逆抑制剂碘乙酸对酶促反应速率的影响 ,发现 2 TeCD催化反应过程中不生成碲醇中间体 .由此推测出 2 TeCD的催化循环经历碲硫化合物、次碲酸硫酯和次碲酸中间体 .该催化循环与含硒GPX小分子模拟物所经历的催化循环不同 ,以及环糊精对底物具有识别与结合的能力 ,可能是 2 TeCD具有高GPX活力的主要原因
Using β-cyclodextrin (CD) as an enzyme model, Te was introduced into β-cyclodextrin to synthesize a new water-soluble and high-activity small-molecule glutathione peroxidase (GPX) The results showed that the GPX activity of 2 TeCD reduced by glutathione (GSH) was 46 7U / μmol, which was in agreement with that reported in the literature Data showed that the GPX activity of 2 TeCD was the highest.The kinetics of H2O2 reduction by 2 TeCD catalyzed GSH reduction showed that the double reciprocal curve of initial velocity vs substrate concentration was a set of parallel lines indicating that the catalyst catalyzed by 2 TeCD Mechanism may be three transfer ping-pong mechanism.We investigated the effect of free radical scavenger 2, 4 di-tert-butyl-methylphenol on the rate of enzymatic and spontaneous reactions and found that 2 TeCD-catalyzed enzymatic reaction is a non-free radical mechanism.We investigated the enzyme irreversible The effect of inhibitor iodoacetic acid on the rate of enzymatic reaction was investigated and it was found that the catalyst of 2 TeCD did not form a tellurol intermediate during the 2 TeCD catalysis reaction.It was deduced that the catalytic cycle of 2 TeCD experienced the reaction of tellurium sulfur compounds, The body Different cycles of the small molecule GPX mimetics selenium experienced by catalytic cycle, and cyclodextrins have the ability to bind to the recognition and the substrate, may be the main reason for having a high 2 TeCD GPX activity in