申请人:THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
公开号:US10829798B2
公开(公告)日:2020-11-10
Traditional enzyme characterization methods are low-throughput, and therefore limit engineering efforts in synthetic biology and biotechnology. Here we propose a DNA-linked enzyme-coupled assay (DLEnCA) to monitor enzyme reactions in a high-throughput manner. Throughput is improved by removing the need for protein purification and by limiting the need for liquid chromatography mass spectrometry (LCMS) product detection by linking enzymatic function to DNA modification. DLEnCA is generalizable for many enzymatic reactions, and here we adapt it for glucosyltransferases, methyltransferases, and oxidoreductases. The assay utilizes cell free transcription/translation systems to produce enzymes of interest, while UDP-Glucose and T4-β-glucosyltransferase are used to modify DNA, which is detected post-reaction using qPCR or similar means of DNA analysis. For monitoring methyltransferases, consumption of SAM is observed by coupling to EcoRI methyltransferase. For monitoring oxidoreductases, consumption of NADH is observed by coupling to Taq or E. coli DNA ligase. OleD and two glucosyltransferases from Arabidopsis were used to verify the assay's generality toward glucosyltransferases. Two methyltransferases from human and Arabidopsis were used to verify the assay's generality towards methyltransferases. We show DLEnCA's utility by mapping out the substrate specificity for these enzymes and observing the multiple steps of a biosynthetic pathway.
传统的酶表征方法通量低,因此限制了合成生物学和生物技术中的工程工作。在这里,我们提出了一种 DNA 链接酶耦合测定法(DLEnCA),以高通量的方式监测酶反应。通过将酶功能与 DNA 修饰联系起来,无需纯化蛋白质,并限制了对液相色谱质谱(LCMS)产品检测的需求,从而提高了通量。DLEnCA 可用于多种酶促反应,在此我们将其用于葡萄糖基转移酶、甲基转移酶和氧化还原酶。该检测方法利用游离细胞转录/翻译系统来产生相关酶,同时利用 UDP-Glucose 和 T4-β- 葡糖基转移酶来修饰 DNA,并在反应后利用 qPCR 或类似的 DNA 分析方法进行检测。在监测甲基转移酶时,可通过与 EcoRI 甲基转移酶偶联来观察 SAM 的消耗情况。为了监测氧化还原酶,可通过与 Taq 或大肠杆菌 DNA 连接酶连接来观察 NADH 的消耗情况。拟南芥中的 OleD 和两种葡萄糖基转移酶被用来验证该检测方法对葡萄糖基转移酶的通用性。来自人类和拟南芥的两种甲基转移酶被用来验证该检测方法对甲基转移酶的通用性。我们通过绘制这些酶的底物特异性图和观察生物合成途径的多个步骤,展示了 DLEnCA 的实用性。