Probing Electron-Induced Bond Cleavage at the Single-Molecule Level Using DNA Origami Templates
Probing Electron-Induced Bond Cleavage at the Single-Molecule Level Using DNA Origami Templates
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DOI：
10.1021/nn3010747
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发表时间：
2012-05-01
期刊：
影响因子：
17.1
通讯作者：
Besenbacher, Flemming
中科院分区：
文献类型：
--
作者：
Keller, Adrian;Bald, Ilko;Besenbacher, Flemming
低能电子（LEE）在纳米光刻、大气化学和DNA辐射损伤中起着重要作用。以前，由LEE引发的特定化学键的断裂已经在各种小有机分子如卤代苯和DNA核碱基中得到证实。在这里，我们提出了一种策略，允许第一次可视化的电子诱导解离的单一化学键内复杂的，但定义明确的自组装DNA纳米结构。我们采用原子力显微镜成像和定量LEE诱导的键解离内专门设计的寡核苷酸靶连接到DNA折纸模板。以这种方式，我们使用高度选择性的方法来比较单个二硫键的电子诱导解离与TT二核苷酸序列内的DNA骨架的更复杂的裂解的效率。这种新技术能够快速和平行地测定DNA链断裂产率，并对DNA的一级和二级结构进行前所未有的控制。因此，在最自然的环境中对DNA辐射损伤的详细研究，例如，构成染色质的DNA核小体，现在变得可行。
Low-energy electrons (LEEs) play an important role in nanolithography, atmospheric chemistry, and DNA radiation damage. Previously, the cleavage of specific chemical bonds triggered by LEEs has been demonstrated in a variety of small organic molecules such as halogenated benzenes and DNA nucleobases. Here we present a strategy that allows for the first time to visualize the electron-induced dissociation of single chemical bonds within complex, but well-defined self-assembled DNA nanostructures. We employ atomic force microscopy to image and quantify LEE-induced bond dissociations within specifically designed oligonucleotide targets that are attached to DNA origami templates. In this way, we use a highly selective approach to compare the efficiency of the electron-induced dissociation of a single disulfide bond with the more complex cleavage of the DNA backbone within a TT dinucleotide sequence. This novel technique enables the fast and parallel determination of DNA strand break yields with unprecedented control over the DNA's primary and secondary structure. Thus the detailed investigation of DNA radiation damage in its most natural environment, e.g., DNA nucleosomes constituting the chromatin, now becomes feasible.