Bioinspired control of protein transport through polymer functionalised nanopores

该项目将启动一项受核孔复合物（NPC）启发的纳米孔蛋白质分离研究计划。NPC是由超过400种蛋白质组成的复杂的巨大组装体，其限定了直径约40 nm的纳米级孔（即纳米孔）。每个NPC跨越核膜，核膜将细胞核和细胞的其余部分分开。NPC是所有真核细胞中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。细胞中所有其他成千上万种无关但相似的分子都被排斥。生物分子的方便分离是一种使能技术。NPC镶嵌的核膜实际上是高度特异性和高效的分子分离和纯化膜。它们每分钟能够在人体内分选超过1公斤的特定生物分子，远远超过当前技术的性能。NPC-mimetic纳米多孔膜的产生将有利于各种生物技术和生物医学应用，从用于床边医疗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功能的科学基础将有助于我们实现这些应用，并帮助我们迎接21世纪世纪医疗保健和先进制造业的挑战。该项目的直接目标是建立实现NPC基本功能的设计规则-使用具有“虚拟”尺寸截止的纳米孔根据大小对蛋白质进行分选，与当前技术不同，不会被与蛋白质的随机相互作用堵塞。NPC的孔径是虚拟的，因为它的物理直径比蛋白质的尺寸大得多。然而，随机蛋白质不能通过，因为每个NPC纳米孔填充有半多孔聚合物塞，该半多孔聚合物塞具有尚未鉴定的结构，该结构特异性排斥蛋白质，除了那些对核功能特异的蛋白质。研究NPC的生物学家提出了两个主要理论来解释塞子是如何工作的：i）“虚拟门”聚合物刷模型，ii）“选择性相”网络模型。该项目将创建用合成聚合物装饰的人工纳米孔作为简化模型来模拟这两种理论结构。实验将进行，以验证是否任何一个理论实际上是可行的。最终目标是利用这些设计规则进一步开发纳米多孔膜平台，该平台包含用于装饰纳米孔的越来越先进的聚合物。这将创造出具有分离效率和选择性的NPC启发的纳米多孔膜，其匹配，甚至可能最终超过天然NPC功能。

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.