Harnessing Nature's ability to create membrane compartmentalisation through redesign of a protein machinery.

一个生物细胞可以被认为是一个复杂的化学反应器，大量的相互作用同时发生；这些对它的功能和生存至关重要。为了防止在所有这些同时发生的化学途径的“噪音”中产生不必要的串扰和干扰，细胞将这些过程区隔化，在单个膜结合结构（细胞器）中定位不同的功能。化学过程的限制也允许细胞维持对每个细胞器功能最优的不相容环境，这在单个“锅”中是不可能的。如果我们要在合成的“纳米反应器”中模拟这种复杂性，或者甚至构建能够在医学、环境修复或能量捕获和储存等不同领域完成有用任务的合成细胞，我们将需要开发出在合成人造结构中模拟细胞区隔化的方法。这是我们在这个项目中要解决的挑战。活细胞内部的膜结合区室通常是由“蛋白质”成分组成的分子机器产生的。我们将重新设计属于其中一种机器的蛋白质结构，以控制其在实验室中制造的膜囊泡的可用性。最终，我们将使用这种基于蛋白质的生物技术来制造包含在更大的膜容器（细胞器）内的纳米反应器。天然存在于高等生物（如人类）中的膜形成机制是由许多协同工作的蛋白质组成的；显然，这种复杂性目前与大规模的分隔架构的实验室工程不兼容。因此，我们项目的第一个目标是设计一个最小的膜形成蛋白质系统，在高等生物膜上工作。在一些古老的细菌中已经观察到这种生物简单性的先例，这些细菌含有由很少的蛋白质成分组成的类似的膜形成机制。我们将模仿这个更简单的模型，通过基因工程，减少已经有很好特征的高等生物复合体的功能成分的数量。这种基于蛋白质的技术将用于开发多室结构，类似于生物细胞，每个室含有不同大小和化学性质的分子。我们将学会控制这种生物技术的膜形成作用，这样我们就能够停止和重新开始新隔室的产生。这将使我们能够在较大的膜结构中控制不同组分在特定隔室中的封装。概念的第一个证明将包括封装一个分子机器，能够将遗传信息转化为新的蛋白质分子在一个单一的内部隔间，模仿细胞核的功能。将进行进一步的工作，以允许在单个容器内的内部隔间之间选择性地移动化学品。这个项目的最终产品将是一个特性良好、功能齐全的工具包，使研究人员能够创建复杂的分区化和通信的纳米反应器。这些装置可以作为细胞大小的载体，同时生产、运输和运送治疗货物到体内的特定目标。或者，它们可以被用作化工厂，可以从供水系统中去除污染物。

A biological cell can be thought of as a complex chemical reactor where vast numbers of interactions are simultaneously taking place; these are vital to its function and survival. To prevent unwanted cross-talk and interference within the "noise" of all these concurrent chemical pathways, a cell compartmentalises these processes localizing different functions within individual membrane-bound structures (organelles). Confinement of chemical processes also allows a cell to maintain incompatible environments that are optimal for each organelle's function, which would not be possible within a single "pot".If we are to mimic this complexity within synthetic "nanoreactors", or even build synthetic cells capable of useful tasks within areas as diverse as medicine, environmental remediation, or energy capture and storage, we will need to develop ways of mimicking cellular compartmentalisation within synthetic man-made structures. This is the challenge we will address in this project.Internal membrane bound compartments within living cells are normally generated by molecular machineries made up of 'protein' components. We will redesign the structure of proteins belonging to one of these types of machineries to control its usability with membrane vesicles made in the laboratory. Ultimately, we will use this protein-based biotechnology to create nanoreactors contained within the larger membrane vessel (organelle). Membrane-shaping machineries naturally occurring in higher organisms, such as humans, are composed of many proteins working in concert; obviously such complexity is not currently compatible with large scale laboratory engineering of compartmentalised architectures. Therefore the first aim of our project is to engineer a minimal membrane-shaping protein system working on higher organism membranes. Precedent for this biological simplicity has been observed in some ancient bacteria containing similar membrane-shaping machineries made up of very few protein components. We will mimic this simpler model by reducing the number of functional components of an already well-characterised higher organism complex, through genetic engineering. This protein-based technology will be used to develop multi-compartment architectures, similar to biological cells, with each compartment containing molecules of different sizes and chemical properties. We will learn to control the membrane shaping action of this biotechnology so that we are able to stop and restart the generation of new compartments. This will allow us to control the encapsulation of different components in specified compartments within the larger membrane structure.A first proof of concept will consist of encapsulating a molecular machinery capable of converting genetic information into new protein molecules inside one single internal compartment, mimicking the function of the cell nucleus. Further work will be conducted to allow selective movement of chemicals between internal compartments within a single vessel. The ultimate product of this project will be a well-characterised, functional toolkit enabling researchers to create complex compartmentalised and communicating nanoreactors. These devices could be used as cell-sized vehicles that simultaneously produce, transport and deliver therapeutic cargo to specific targets in the body. Alternatively, they could be employed as chemical factories that can remove pollutants from water supplies.