Folding‐upon‐Repair DNA Nanoswitches for Monitoring the Activity of DNA Repair Enzymes
Folding‐upon‐Repair DNA Nanoswitches for Monitoring the Activity of DNA Repair Enzymes
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折叠修复 DNA 纳米开关用于监测 DNA 修复酶的活性
DOI：
10.1002/ange.202016223
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发表时间：
2021
影响因子：
--
通讯作者：
Ricci, Francesco
中科院分区：
文献类型：
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作者：
Farag, Nada;Mattossovich, Rosanna;Merlo, Rosa;Nierzwicki, Łukasz;Palermo, Giulia;Porchetta, Alessandro;Perugino, Giuseppe;Ricci, Francesco
我们提出了一类新的基于DNA的纳米开关，在酶修复后，可以经历构象变化机制，导致荧光信号的变化。这种修复后折叠的DNA纳米开关是含有O 6-甲基鸟嘌呤（O 6-MeG）核碱基的合成DNA序列，并用荧光团/猝灭剂光学对标记。纳米开关被合理地设计，使得只有在O 6-MeG核碱基的酶促去甲基化后，它们才能形成稳定的分子内Hoogsteen相互作用并折叠成光学活性的三链DNA结构。我们首先通过荧光实验和分子动力学模拟表征了酶修复活性诱导的折叠机制。然后，我们证明了修复后折叠DNA纳米开关是不同甲基转移酶（包括人类同源物（hMGMT））的合适和特异性底物，并且它们允许筛选新的潜在甲基转移酶抑制剂。
We present a new class of DNA‐based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding‐upon‐repair DNA nanoswitches are synthetic DNA sequences containingO6‐methyl‐guanine (O6‐MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation of theO6‐MeG nucleobases they can form stable intramolecular Hoogsteen interactions and fold into an optically active triplex DNA structure. We have first characterized the folding mechanism induced by the enzymatic repair activity through fluorescent experiments and Molecular Dynamics simulations. We then demonstrated that the folding‐upon‐repair DNA nanoswitches are suitable and specific substrates for different methyltransferase enzymes including the human homologue (hMGMT) and they allow the screening of novel potential methyltransferase inhibitors.