Highly Polyvalent DNA Motors Generate 100+pN of Force via Autochemophoresis
Highly Polyvalent DNA Motors Generate 100+pN of Force via Autochemophoresis
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DOI：
10.1021/acs.nanolett.9b02311
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发表时间：
2019-10-01
期刊：
影响因子：
10.8
通讯作者：
Salaita, Khalid
中科院分区：
文献类型：
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作者：
Blanchard, Aaron T.;Bazrafshan, Alisina S.;Salaita, Khalid
马达蛋白如肌球蛋白、驱动蛋白和动力蛋白是真核生物生命所必需的，并且为无数过程提供动力，包括肌肉收缩、伤口闭合、货物运输和细胞分裂。设计能够复制这些马达功能的合成纳米机器是纳米技术领域的一个长期目标。DNA步行者，通过烧桥布朗棘轮机制，被编程为沿着沿着定义的轨道“行走”，是这些马达蛋白最有前途的合成模拟物之一。虽然这些基于DNA的马达可以执行有用的任务，如货物运输，但它们尚未被证明能够合作产生类似肌肉收缩的任务的大集体力。在这项工作中，我们证明了高度多价DNA马达（HPDM），这可以被视为成千上万的DNA步行者连接到一个微球的合作团队，可以产生和维持在100+ pN制度的实质性的力量。具体而言，我们表明HPDM可以产生可以解压缩和剪切DNA双链体（分别类似于12和类似于50 pN）和破坏生物素-链霉亲和素键（类似于100-150 pN）的力。为了帮助解释这些结果，我们提出了一个变体的烧桥布朗棘轮机制，我们称之为autochemophoresis，其中许多单独的力产生单元产生一个自传播的化学力学梯度，产生大的集体力量。此外，我们证明了这项工作的潜力，影响未来的工程应用，利用HPDM自化学泳存款“分子墨水”通过机械键断裂。这项工作扩展了合成DNA马达的能力，以模仿生物马达的力产生功能。我们的工作也建立在以前的观察autochemophoresis在细菌的运输过程中，表明autochemophoresis可能是一个基本的机制PN规模的力量产生的生活系统。
Motor proteins such as myosin, kinesin, and dynein are essential to eukaryotic life and power countless processes including muscle contraction, wound closure, cargo transport, and cell division. The design of synthetic nanomachines that can reproduce the functions of these motors is a longstanding goal in the field of nanotechnology. DNA walkers, which are programmed to "walk" along defined tracks via the burnt bridge Brownian ratchet mechanism, are among the most promising synthetic mimics of these motor proteins. While these DNA-based motors can perform useful tasks such as cargo transport, they have not been shown to be capable of cooperating to generate large collective forces for tasks akin to muscle contraction. In this work, we demonstrate that highly polyvalent DNA motors (HPDMs), which can be viewed as cooperative teams of thousands of DNA walkers attached to a microsphere, can generate and sustain substantial forces in the 100+ pN regime. Specifically, we show that HPDMs can generate forces that can unzip and shear DNA duplexes (similar to 12 and similar to 50 pN, respectively) and rupture biotin-streptavidin bonds (similar to 100-150 pN). To help explain these results, we present a variant of the burnt-bridge Brownian ratchet mechanism that we term autochemophoresis, wherein many individual force generating units generate a self-propagating chemomechanical gradient that produces large collective forces. In addition, we demonstrate the potential of this work to impact future engineering applications by harnessing HPDM autochemophoresis to deposit "molecular ink" via mechanical bond rupture. This work expands the capabilities of synthetic DNA motors to mimic the force-generating functions of biological motors. Our work also builds upon previous observations of autochemophoresis in bacterial transport processes, indicating that autochemophoresis may be a fundamental mechanism of pN-scale force generation in living systems.