21ENGBIO: Engineering novel amyloid biofilm based material for capture and degradation of micro-plastics

21ENGBIO：工程新型淀粉样生物膜材料用于捕获和降解微塑料

• 批准号: BB/W011530/1
• 负责人: Wei-Feng Xue
• 金额: $ 12.81万
• 依托单位: University of Kent
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FW011530%2F1
• 关键词: 21ENGBIO; Engineering; novel; amyloid; biofilm

Plastic pollution, whereby plastic objects and particles are accumulated is a current, pressing, and costly environmental problem both in the UK and worldwide. Polyethylene terephthalate (PET) is the chemical name for polyester, a common type of plastic which would take up to 800 years to degrade on its own. PET waste also tends to be converted by abrasion into microplastics, which are known to have adverse effects on animals and plants. Recently, researchers have discovered an enzyme called PETase which can actively degrade PET into non-harmful substances. Currently, the application of PETases to plastic degradation is limited by the requirement to deploy PETases in solution. We propose combining PETases with a meshed biomaterial formed from amyloid fibrils to form a novel material. This material can be exported via bioengineered cells to generate a non-toxic mesh with malleable properties for potential use in large scale designs to remove and to degrade plastic waste.Amyloid fibrils are a type of protein structures with a characteristic shape. Some amyloid fibrils are known to be associated with diseases such as Alzheimer's disease, Parkinson's disease, and systemic amyloidosis. However, many amyloid forming are beneficial, or "functional" in that they fill essential biological roles. Bacteria such as E. coli have been found to utilise amyloid fibrils made from the curli protein to form a protective biofilm as the amyloid fibrils form a hard to pass through mesh which protects the E. coli against viral infection. To do this, the E. coli cells naturally contain a system which forces the amyloid fibrils to form outside the cells in a controlled manner by sticking individual curli proteins together as they are pushed out of the cell. It is already possible to hijack this system to export amyloid fibrils made from different amyloidogenic proteins, for example another functional amyloid protein from yeast called Sup35.Sup35 forms amyloid fibrils in yeast cells and normally is then used as a messenger to other yeast cells. Importantly, Sup35 has three parts and only two of these are required to make the amyloid fibrils, these two parts are known as Sup35NM. We intend to replace the 3rd part with enzymes such as PETase which could functionalise the Sup35NM amyloid fibrils and imbue them with PET degrading functionality.In this project, we intend to bioengineer E. coli cells to generate and export a biofilm containing the novel material of Sup35NM amyloid fibrils decorated with PETase and other plastics degrading enzymes. This will generate a robust yet malleable, non-toxic substance which could be applied to devices such as filters or even 3D printed onto complex designs with the ability to degrade plastics. Since neither plastics nor amyloid interact well with water, the amyloid mesh will likely be able to capture and to improve the contact between the plastic degrading enzymes and the plastic particles. Furthermore, the very high density of enzymes that can be achieved in an amyloid mesh will further improve plastic degradation, and the ability to combine different types of enzymes may improve the total plastic degradation activity. The proposed amyloid mesh, therefore, could offer an environmental solution to the problem of plastic pollution.

塑料污染（堆积塑料物体和颗粒）在英国和全球范围内都是当前，紧迫且昂贵的环境问题。聚对苯二甲酸酯（PET）是聚酯的化学名称，这是一种常见的塑料类型，最多需要800年才能自行降解。宠物废物还倾向于将磨损转化为微塑料，这些微塑料对动物和植物有不利影响。最近，研究人员发现了一种名为PETASE的酶，该酶可以主动将PET降解为无害物质。当前，对塑料降解的应用在溶液中部署Petass的要求限制。我们提出将小叶酸与由淀粉样蛋白原纤维形成的网状生物材料结合在一起，以形成一种新型材料。该材料可以通过生物工程细胞出口，以生成具有可延展特性的无毒网状，以便在大规模设计中使用以去除和降解塑料废物。淀粉样蛋白原纤维是具有特征形状的蛋白质结构。一些淀粉样蛋白原纤维与诸如阿尔茨海默氏病，帕金森氏病和全身性淀粉样变性等疾病有关。但是，许多淀粉样蛋白形成是有益的，或者“功能性”，因为它们填补了重要的生物学作用。已经发现细菌（例如大肠杆菌）利用由Curli蛋白制成的淀粉样蛋白原纤维形成保护性生物膜，因为淀粉样蛋白原纤维形成很难通过网状，从而可以保护大肠杆菌免受病毒感染的侵害。为此，大肠杆菌细胞自然包含一个系统，该系统迫使淀粉样蛋白原纤维以受控方式将单个卷蛋白粘在细胞中时，以受控的方式形成细胞。已经可以劫持该系统以导出由不同淀粉样蛋白制成的淀粉样蛋白原纤维，例如，从酵母中的另一种功能性淀粉样蛋白Sup355.Sup35形成酵母细胞中的淀粉样蛋白原纤维，然后通常用作其他酵母细胞的使者。重要的是，Sup35具有三个部分，其中只有两个需要制作淀粉样蛋白原纤维，这两个部分被称为Sup35nm。我们打算用诸如PETASE之类的酶代替第三部分，该酶可以使Sup35nm淀粉样蛋白原纤维运行，并将它们与PET降解功能相关。这将产生强大但可延展的无毒物质，该物质可以应用于过滤器，甚至3D印刷在复杂设计上，能够降解塑料。由于塑料和淀粉样蛋白都与水相互作用都没有很好地相互作用，因此淀粉样蛋白网状网状物可能能够捕获并改善塑料降解酶与塑料颗粒之间的接触。此外，可以在淀粉样蛋白网格中实现的极高密度将进一步改善塑性降解，并且结合不同类型的酶的能力可以改善总塑料降解活性。因此，拟议的淀粉样蛋白网状物可以为塑料污染问题提供环境解决方案。