Placing molecules with Bohr radius resolution using DNA origami
Placing molecules with Bohr radius resolution using DNA origami
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DOI：
10.1038/nnano.2015.240
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发表时间：
2016-01-01
影响因子：
38.3
通讯作者：
Dietz, Hendrik
中科院分区：
文献类型：
--
作者：
Funke, Jonas J.;Dietz, Hendrik
核酸分子自组装可用于制造具有确定尺寸和任意形状的离散物体（1,2）。它依赖于与生物大分子机器相称的构建块，因此应该能够提供目前仅从天然和设计的蛋白质中知道的原子尺度的放置精度（3,4）。然而，该领域的研究主要集中在生产越来越大和复杂，但更粗略定义的物体（5-10），并以有序的方式将它们放置在固体基板上（11,12）。到目前为止，很少有物体能够提供超过5纳米的设计精度（13-16），而亚纳米尺度仅在设计的DNA晶体的单位细胞内达到（17）。在这里，我们报告了一种分子定位装置，由铰链DNA折纸物体制成，其中两个结构单元之间的角度可以通过调节螺旋来控制。为了测试设备的定位能力，我们使用光物理和交联分析，直接以原子分辨率报告感兴趣的坐标。利用这种放置和分析相结合的方法，我们在123个离散位移步骤中合理地调整了荧光分子与反应基团之间的平均距离，从1.5 nm调整到9 nm。最小位移步长为0.04 nm，略小于玻尔半径。距离坐标的波动幅度也很小（+/- 0.5 nm），是蛋白质结构波动幅度的两到三倍（18）。
Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes(1,2). It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins(3,4). However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects(5-10) and placing them in an orderly manner on solid substrates(11,12). So far, few objects afford a design accuracy better than 5 nm(13-16), and the sub-nanometre scale has been reached only within the unit cells of designed DNA crystals(17). Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (+/- 0.5 nm), and within a factor of two to three of the amplitudes found in protein structures(18).