DNA支架指导的病毒蛋白可编程动态组装调控

Biomolecules, as unique natural nanomaterials, have great potential in self-assembling into complex operating device by rational design and reengineering, which can be used in many applications, such as molecular imaging, biosensing, drug delivery, etc. In particular, protein and nucleic acid are the most important components for physical foundation and functional units in life system, and their intrinsic assembly mechanism bring valuable opportunity to construct artificial intelligence nanomachine, but there is still a huge challenge. Herein, we utilize engineered DNA origami as scaffold to route RNA strand, and thus realize addressable assembly of virus protein modules on DNA origami on the basis of protein-protein and protein-RNA coordination interaction derived from inherent packaging mechanism of virus. Then the toehold-mediated strand exchange is employed to release RNA motif and precisely control the growth status and sliding position of nucleoprotein assembly, whereby generating a routing assembly system with programmable dynamic control. In this project, DNA nanotechnology is used to tailor the uncontrollable virus packaging procedure by adding nucleic acid guided programmability, which endows the whole system with more controllability and addressability. Our strategy breaks though the common limitation in noncovalent self-assembly of ordered multi-components, which is expected to offer an effective approach for mimicking in vivo self-assembly pattern of functional biodevices and to inspire orientation control means for the fabrication of intelligent supermolecule assemblies using biomaterials.

生物分子作为独特的天然纳米材料，具有理性设计、改造并进行自组装制造复杂操纵元件的巨大潜力，在分子影像、生物传感和药物运输等许多领域表现出诱人的应用前景。其中，蛋白质和核酸是构成生命体物质基础与功能单位的最重要成份，其内在组装模式为人工构建智能化纳米器件提供了重要契机,但仍有巨大的挑战。本项目利用设计的DNA支架实现RNA链的路径化排布，借助病毒增殖机制中蛋白质-蛋白质、蛋白质-RNA协作机制实现病毒蛋白模块在DNA支架上的定点装配；再通过核酸链置换控释机制，实现核蛋白组装体生长和位移的精确操控，发展一种可编程的路径依赖型动态组装系统。本项目基于DNA纳米技术将难以调控的病毒装配程序转化为编程性更强的核酸控制过程，赋予系统更高的可控性和空间编码能力。这种策略突破了多组分非共价组装限制，为今后模拟体内功能结构的自组装行为提供了有效借鉴，也是生物材料制备定向控制的智能超分子体系方面的有益尝试。

纳米尺度生物体的人为可控组装是纳米技术研究的重要基础问题之一。病毒和病毒样纳米颗粒可作为研究可控自组装行为的良好体系。在本研究中我们利用DNA支架对病毒基因组相关RNA序列的活性状态进行了巧妙设计，实现烟草花叶病毒（TMV）蛋白组装步骤的动态调控。首先，通过DNA origami上伸出的互补交联序列的设计，进行RNA长链的捕获研究，实现RNA的有序排布。RNA长链上伸出的病毒组装起始引导序列结合TMV病毒衣壳蛋白亚基，启动持续组装直至到达DNA origami支架表面而暂停。通过控制DNA origami支架表面固定链的有序打开，逐步释放预定长度的RNA基序，不仅可以实现蛋白组装程序的精确控制，还能操纵组装体按预定路线进行实时精确移动。这个策略了实现了病毒蛋白可控动态组装，为构筑新型核酸-蛋白复合机器奠定重要基础。