Aptamer-Braked Multi-Hairpin Cascade Circuits for Logic-Controlled Label-Free in Situ Bioimaging.
Aptamer-Braked Multi-Hairpin Cascade Circuits for Logic-Controlled Label-Free in Situ Bioimaging.
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DOI：
10.1021/acs.analchem.0c00583
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发表时间：
2020-06
影响因子：
7.4
通讯作者：
Zhijin Tian;Pai Peng;Huihui Wang;Jiao Zheng;Lili Shi;Tao Li
中科院分区：
文献类型：
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作者：
Zhijin Tian;Pai Peng;Huihui Wang;Jiao Zheng;Lili Shi;Tao Li
作为一种常见的基于发夹的fi扩增策略，催化发夹组装已被广泛应用于构建各种生物传感和成像的DNA电路。然而，发夹底物可能在没有催化剂的情况下发生反应并导致电路泄漏，这在由三个或四个发夹组成的CHA反应中可能非常严重，因为形成了稳定的三路/四路连接产物。为了避免这一问题，我们在四发卡级联电路中引入了一种精心设计的ATP适配子作为DNA制动器，其中触发脚点被适配子制动器阻挡，从而大大减少了电路泄漏。然后，在酸性细胞膜微环境中，利用这种适配子制动的DNA电路来构建与逻辑门，以响应多种外部刺激。在结合硫黄素T(THT)的双分子基序诱导下，细胞表面原位组装的四向连接完成了二聚化，使得逻辑控制的细胞膜成像能够以无标记的方式进行。我们的设计将适用于其他基于发夹的fi扩增策略，并可能在构建复杂生命系统中的多响应DNA级联电路中得到更多的应用。
As a common hairpin-based amplification strategy, catalytic hairpin assembly (CHA) has been widely used to construct various DNA circuits for biosensing and imaging. However, the hairpin substrates can potentially react without catalysts and result in circuit leakage, which may be quite severe in a CHA reaction consisting of three or four hairpins due to the formation of stable three-/four-way junction product. To circumvent this problem, here we introduce a well-designed ATP aptamer as a DNA brake into a four-hairpin cascade circuit, where the triggering toehold is blocked by the aptamer brake and thus the circuit leakage decreases dramatically. Such an aptamer-braked DNA circuit is then employed to build an AND logic gate in response to multiple external stimuli in acidic cell membrane microenvironments. Induced by a bimolecular i-motif that binds thioflavin T (ThT), the dimerization of a four-way junction in situ assembled on the cell surface is accomplished, enabling the logic-controlled cell membrane imaging in a label-free manner. Our design would be applicable to other hairpin-based amplification strategies, and may find more applications in the construction of multi-responsive DNA cascade circuits in complex living systems.