Programming a topologically constrained DNA nanostructure into a sensor.
Programming a topologically constrained DNA nanostructure into a sensor.
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DOI：
10.1038/ncomms12074
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发表时间：
2016-06-23
影响因子：
16.6
通讯作者：
Li Y
中科院分区：
文献类型：
--
作者：
Liu M;Zhang Q;Li Z;Gu J;Brennan JD;Li Y
许多合理设计的DNA纳米结构使用机械互锁拓扑结构来连接单个DNA组分，并且它们的物理连接通过形成强连接双链体来实现。这样的结构元素的存在也构成了一个重要的拓扑约束的功能组件环。在此，我们假设并证实，DNA链烷与一个强大的连接双链体阻止组件环作为模板的滚环扩增（RCA）。然而，通过使用具有强连接双链体的含RNA的DNA [2]链烷，我们表明刺激响应性RNA切割DNA酶可以线性化一个组分环，从而实现RCA，产生超灵敏的生物传感系统。作为一个例子，DNA链烷生物传感器被设计成通过分泌蛋白的结合来检测模式细菌病原体大肠杆菌，检测限为10个细胞ml-1，从而为机械联锁DNA纳米结构的进一步应用建立了新的平台。 具有互锁拓扑结构的DNA纳米结构往往会表现出与线性对应物不同的行为。在这里，作者展示了一种对滚环扩增无活性但在一个环裂解时被激活的DNA链烷，并将其用于生物传感系统的开发。
Many rationally engineered DNA nanostructures use mechanically interlocked topologies to connect individual DNA components, and their physical connectivity is achieved through the formation of a strong linking duplex. The existence of such a structural element also poses a significant topological constraint on functions of component rings. Herein, we hypothesize and confirm that DNA catenanes with a strong linking duplex prevent component rings from acting as the template for rolling circle amplification (RCA). However, by using an RNA-containing DNA [2] catenane with a strong linking duplex, we show that a stimuli-responsive RNA-cleaving DNAzyme can linearize one component ring, and thus enable RCA, producing an ultra-sensitive biosensing system. As an example, a DNA catenane biosensor is engineered to detect the model bacterial pathogen Escherichia coli through binding of a secreted protein, with a detection limit of 10 cells ml−1, thus establishing a new platform for further applications of mechanically interlocked DNA nanostructures. DNA nanostructures with interlocked topologies will tend to display different behaviour to the linear counterparts. Here, the authors show a DNA catenane that is inactive for rolling circle amplification but is activated upon cleavage of one ring, and exploit this for the development of a biosensing system.