Towards multistep nanostructure synthesis: Programmed enzymatic self-assembly of DNA/gold systems
Towards multistep nanostructure synthesis: Programmed enzymatic self-assembly of DNA/gold systems
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DOI：
10.1002/anie.200390075
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发表时间：
2003-01-01
影响因子：
16.6
通讯作者：
Brust, M
中科院分区：
文献类型：
--
作者：
Kanaras, AG;Wang, ZX;Brust, M
纳米结构的程序化自组装是纳米科学的一个重要目标。[1，2]使用由硫醇修饰的DNA稳定的金纳米颗粒是实现这一目标的有希望的方法。DNA碱基配对的特异性提供了一种精确的方法，通过与专门设计的连接链杂交来编程颗粒之间的相互作用。为了引入额外的控制水平，我们开发了一种通用方法，通过该方法可以有意地打开最初潜伏的DNA连接位点的反应性。我们已经采用了成熟的分子生物学方法来生产纳米级的保护基团类似物。我们表明，连接位点可以通过与互补链杂交来保护，并通过用限制性内切酶在预定位点切割这些双链来脱保护。这导致单链DNA的粘性末端，其可以通过杂交与系统中存在的互补序列结合。在第二个酶促步骤中，使用DNA连接酶共价连接杂交位点处的DNA磷酸二酯主链。这种方法代表了一种通用的协议，将使多步纳米结构合成。除了DNA之外，已经利用了进一步的生物分子相互作用用于程序化组装。这些包括其他特异性识别基序，如抗体结合抗原和生物素结合亲和素结合。[8]还报道了许多具有不同复杂程度的非生物分子系统。[12这些方法的共同点通常是结合位点的反应性由系统的初始设计决定。反应一旦开始，就继续进行，直到所有的反应位点都通过与互补基序结合而被消耗。这基本上将编程的纳米结构组装限制为单步反应。相反，现代制备化学的特点是复杂的多步合成，这可以通过选择性地处理某些反应位点而其他位点暂时不反应来进行。这是通过使用保护基来实现的，保护基对于几乎所有现代化学合成都是必不可少的。在这里，我们介绍了一个类似的概念，程序化的纳米结构组装，它使用的限制性位点作为保护的连接基序和限制性内切酶作为选择性脱保护剂的双链DNA。图1中示意性地示出了为证明该原理而进行的完整反应顺序。
The programmed self-assembly of nanostructures from welldefined units is an important aim in nanoscience.[1, 2] The use of gold nanoparticles stabilized by thiol-modified DNA is a promising approach towards this goal.[3ą8] The specificity of DNA base-pairing provides a precise means of programming interactions between particles by hybridization with specifically designed linker strands. To introduce an additional level of control, we have developed a general method by which the reactivity of initially latent DNA linking sites can be switched on deliberately. We have adapted well-developed methods of molecular biology to produce a nanoscale analogue of protecting groups. We show that linking sites can be protected by hybridization with complementary strands and deprotected by cleaving these double strands at predetermined sites with restriction enzymes. This results in cohesive ends of single-stranded DNA, which can bind by hybridization to complementary sequences present in the system. In a second enzymatic step the DNA phosphodiester backbones at the hybridization sites are covalently joined using a DNA ligase. This approach represents a generic protocol that will enable multistep nanostructure syntheses. In addition to DNA, further biomolecular interactions have been exploited for programmed assembly. These include other specific recognition motifs such as antibodyąantigen and biotinąavidin binding.[8ą11] A number of nonbiomolecular systems with various degrees of complexity have also been reported.[12ą16] These approaches generally have in common that the reactivity of the binding sites is determined by the initial design of the system. A reaction, once started, proceeds until all reactive sites have been consumed by binding to complementary motifs. This essentially limits programmed nanostructure assembly to single-step reactions. Conversely, modern preparative chemistry is characterized by complex multistep syntheses, which can routinely be carried out by selectively addressing certain reactive sites while others are left temporarily unreactive. This is achieved by the use of protecting groups, which are essential to practically all modern chemical syntheses. Here we introduce a comparable concept to programmed nanostructure assembly, which uses the restriction sites in double-stranded DNA as protected linking motifs and restriction endonucleases as selective deprotecting agents. The complete reaction sequence carried out to demonstrate this principle is illustrated schematically in Figure 1.