A self-cleaving DNA enzyme modified with amines, guanidines and imidazoles operates independently of divalent metal cations (M2+).
A self-cleaving DNA enzyme modified with amines, guanidines and imidazoles operates independently of divalent metal cations (M2+).
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DOI：
10.1093/nar/gkn1070
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发表时间：
2009-04
影响因子：
14.9
通讯作者：
Perrin DM
中科院分区：
文献类型：
--
作者：
Hollenstein M;Hipolito CJ;Lam CH;Perrin DM
选择修饰的DNAzyme代表了在扩大催化核酸的化学和催化性能方面的重要努力。这样的例子很少，而且到目前为止，还没有三个不同的修饰碱基同时结合用于催化活性的例子。在这篇论文中，dCTP、dATP和dUTP分别以阳离子胺、咪唑和阳离子胍为模板，在DNAzyme 9-86上进行酶促聚合，以选择一种在生理条件下催化(M2+)非依赖于(M2+)自切割的脱氧核酶DNAzyme 9-86，其速率常数为(0.134±0.026)min−1。与以前观察到的只含有胺和咪唑的脱氧核酶相比，存在的胍阳离子允许在显著更高的温度下进行切割。定性上，DNAzyme 9-86提供了前所未有的合成功能，而定量上，当在37°C的无M2+条件下研究时，它表达了任何自裂解核酸的最高值之一。
The selection of modified DNAzymes represents an important endeavor in expanding the chemical and catalytic properties of catalytic nucleic acids. Few examples of such exist and to date, there is no example where three different modified bases have been simultaneously incorporated for catalytic activity. Herein, dCTP, dATP and dUTP bearing, respectively, a cationic amine, an imidazole and a cationic guanidine, were enzymatically polymerized on a DNA template for the selection of a highly functionalized DNAzyme, called DNAzyme 9-86, that catalyzed (M2+)-independent self-cleavage under physiological conditions at a single ribo(cytosine)phosphodiester linkage with a rate constant of (0.134 ± 0.026) min−1. A pH rate profile analysis revealed pKa's of 7.4 and 8.1, consistent with both general acid and base catalysis. The presence of guanidinium cations permits cleavage at significantly higher temperatures than previously observed for DNAzymes with only amines and imidazoles. Qualitatively, DNAzyme 9-86 presents an unprecedented ensemble of synthetic functionalities while quantitatively it expresses one of the highest reported values for any self-cleaving nucleic acid when investigated under M2+-free conditions at 37°C.
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影响因子：
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作者：
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通讯作者：
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