Zhang Chuan, Su Min, He Yu, Zhao Xin, Fang Ping-an, Ribbe Alexander E, Jiang Wen, Mao Chengde
Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
Proc Natl Acad Sci U S A. 2008 Aug 5;105(31):10665-9. doi: 10.1073/pnas.0803841105. Epub 2008 Jul 30.
Molecular self-assembly is a promising approach to the preparation of nanostructures. DNA, in particular, shows great potential to be a superb molecular system. Synthetic DNA molecules have been programmed to assemble into a wide range of nanostructures. It is generally believed that rigidities of DNA nanomotifs (tiles) are essential for programmable self-assembly of well defined nanostructures. Recently, we have shown that adequate conformational flexibility could be exploited for assembling 3D objects, including tetrahedra, dodecahedra, and buckyballs, out of DNA three-point star motifs. In the current study, we have integrated tensegrity principle into this concept to assemble well defined, complex nanostructures in both 2D and 3D. A symmetric five-point-star motif (tile) has been designed to assemble into icosahedra or large nanocages depending on the concentration and flexibility of the DNA tiles. In both cases, the DNA tiles exhibit significant flexibilities and undergo substantial conformational changes, either symmetrically bending out of the plane or asymmetrically bending in the plane. In contrast to the complicated natures of the assembled structures, the approach presented here is simple and only requires three different component DNA strands. These results demonstrate that conformational flexibility could be explored to generate complex DNA nanostructures. The basic concept might be further extended to other biomacromolecular systems, such as RNA and proteins.
分子自组装是制备纳米结构的一种很有前景的方法。尤其是DNA，它显示出成为一个卓越分子系统的巨大潜力。合成DNA分子已被设计组装成各种各样的纳米结构。人们普遍认为，DNA纳米基元（瓦片）的刚性对于定义明确的纳米结构的可编程自组装至关重要。最近，我们已经表明，可以利用适当的构象灵活性，用DNA三点星形基元组装三维物体，包括四面体、十二面体和巴基球。在当前的研究中，我们将张拉整体原理融入到这个概念中，以在二维和三维中组装定义明确的复杂纳米结构。一种对称的五点星形基元（瓦片）已被设计成根据DNA瓦片的浓度和灵活性组装成二十面体或大型纳米笼。在这两种情况下，DNA瓦片都表现出显著的灵活性，并经历大量的构象变化，要么对称地弯曲出平面，要么不对称地在平面内弯曲。与组装结构的复杂性质形成对比的是，这里提出的方法很简单，只需要三种不同的组成DNA链。这些结果表明，可以探索构象灵活性来生成复杂的DNA纳米结构。这个基本概念可能会进一步扩展到其他生物大分子系统，如RNA和蛋白质。
