Bioinspired control of protein transport through polymer functionalised nanopores

该项目将启动一项受核孔复合物（NPC）启发的纳米孔蛋白分离研究计划。npc是由400多种蛋白质组成的复杂的巨型组件，这些蛋白质定义了直径约40纳米的纳米级孔（即纳米孔）。每个鼻咽癌跨越核膜，核膜将细胞核和细胞的其余部分分开。在所有真核细胞中，npc是进出细胞核的唯一通道，它们只允许一小部分与细胞核功能相关的特定蛋白质和遗传物质通过。细胞中其他数千种不相关但相似的分子都被排斥了。生物分子的便捷分离是一项使能技术。核钉膜是一种高效、特异的分子分离纯化膜。它们每分钟能够对人体中超过1公斤的特定生物分子进行分类，远远超过了现有技术的性能。模仿npc的纳米多孔膜的创建将有利于多种生物技术和生物医学应用，从床边医学诊断的蛋白质疾病标记物的纯化到酶和蛋白质治疗剂的连续制造。了解NPC功能背后的科学将帮助我们实现这些应用，并帮助我们应对21世纪在医疗保健和先进制造业方面的挑战。这个项目的直接目标是建立设计规则，以实现NPC的基本功能——使用纳米孔根据大小对蛋白质进行分类，纳米孔的“虚拟”大小被切断，与目前的技术不同，纳米孔不会被与蛋白质的随机相互作用所堵塞。NPC的孔径是虚拟的，因为它的物理直径比蛋白质的大小大得多。然而，随机蛋白质不能通过，因为每个NPC纳米孔都充满了半多孔聚合物塞，这种聚合物塞的结构尚未确定，可以特异性地排斥蛋白质，除了那些特定于细胞核功能的蛋白质。研究NPC的生物学家提出了两种主要理论来解释插头是如何工作的：i)“虚拟门”聚合物刷模型，ii)“选择相”网络模型。这个项目将创造人工纳米孔，用合成聚合物装饰，作为模拟这两种理论结构的简化模型。将进行实验来验证这两种理论中的任何一种实际上是否可行。最终目标是利用这些设计规则进一步开发纳米孔膜平台，其中包含越来越先进的聚合物来装饰纳米孔。这将创造出受NPC启发的纳米孔膜，其分离效率和选择性与天然NPC的功能相匹配，甚至最终可能超过。

This project will initiate a research programme in nanopore protein separation that is inspired by the nuclear pore complex (NPC). NPCs are complex, giant assemblies constituted from more than 400 proteins that define nanoscale pores (i.e. nanopores) ~40 nm in diameter. Each NPC spans the nuclear membrane which separates the cell nucleus and the rest of the cell. NPCs are the only conduits in and out of the cell nucleus in all eukaryotic cells and they allow only a small set of specific proteins and genetic material related to the functioning of the cell nucleus to pass through. All the other thousands of species of unrelated but similar molecules in the cell are rejected. Convenient separation of biomolecules is an enabling technology. NPC-studded nuclear membranes are effectively a highly specific and efficient molecular separation and purification membrane. They are capable of sorting through more than 1 kg of specific biomolecules in a human body per minute, far surpassing the performance of current technology. The creation of NPC-mimetic nanoporous membranes would benefit diverse biotechnology and biomedical applications, ranging from purification of protein disease markers for bedside medical diagnosis to continuous manufacturing of enzymes and protein therapeutics. Understanding the science underlying NPC function will help us achieve these applications and help us meet our 21st century challenges in healthcare and advanced manufacturing.The immediate goal of this project is to establish the design rules for enabling the basic function of the NPC - the sorting of proteins according to size using nanopores with a "virtual" size cut off and which, unlike current technology, are not clogged by random interactions with proteins. The pore size of the NPC is virtual because it has a physical diameter much larger than the size of the protein. A random protein cannot however pass through because each NPC nanopore is filled with a semi-porous polymer plug with an as yet unidentified structure that specifically repels proteins, except for those proteins specific to nuclear function. Biologists studying the NPC have proposed two leading theories to explain how the plug works: i) the "virtual gate" polymer brush model, and ii) the "selective phase" meshwork model. This project will create artificial nanopores that are decorated with synthetic polymers as simplified models to mimic these two theoretical structures. Experiments will be conducted to verify whether either of the theories is in fact feasible. The ultimate goal is to exploit these design rules for further development of the nanoporous membrane platform that incorporate increasingly advanced polymers for decorating the nanopores. This will create NPC-inspired nanoporous membranes with separation efficiency and selectivity that matches, and may eventually even surpass, native NPC function.