Capture and degradation of micro-plastics by a synthetic biology approach to engineer novel PET-degrading enzyme linked amyloid nano-material

微塑料废物在环境中的积累是一个昂贵且持续的社会挑战，可以通过最近发现的能够降解聚对苯二甲酸乙二醇酯（PET）并将其回收到其组成构件中的酶来解决。然而，目前不存在利用这些酶的有效材料应用。该项目将使用合成生物学方法来设计一种新型生物材料，该生物材料基于将PET降解酶连接到由酵母蛋白Sup 35 NM形成的功能性淀粉样蛋白原纤维上作为支架。淀粉样原纤维是一种具有特征性纤维形状的蛋白质结构。众所周知，一些淀粉样蛋白原纤维与诸如阿尔茨海默病、帕金森病和系统性淀粉样变性的疾病相关。然而，许多淀粉样蛋白结构是有益的，或“功能性的”，因为它们发挥了重要的生物学作用，例如来自面包酵母的功能性淀粉样蛋白Sup 35。Sup 35在酵母细胞中形成淀粉样纤维，这使得它能够正常发挥分子开关的作用。重要的是，Sup 35有三个部分，其中只有两个是制造淀粉样纤维所需的，这两个部分被称为Sup 35 NM。我们打算用酶如PETase代替第三部分，其可以使Sup 35 NM淀粉样纤维功能化并使其具有PET降解功能。Xue和von der Haar实验室的合作工作已经产生了第一个Sup 35 NM-PETase WT融合蛋白，证明了该项目的可行性和培训潜力。在这个项目中，成功的博士候选人将产生新的融合蛋白，其中包含最近发现的PETase序列，这些序列具有增强其活性的突变。然后，他们将组装合成长丝以及网状物，并对所制造材料的结构和PET降解活性进行表征。

Accumulation of microplastic waste in the environment is a costly and ongoing societal challenge that can potentially be addressed through the recent discovery of enzymes that are able to degrade Polyethylene terephthalate (PET) and recycle it into its constituent building blocks. However, no efficient materials applications currently exist that utilise these enzymes. This project will use a synthetic biology approach to engineer a novel biomaterial based on linking PET degrading enzymes onto functional amyloid fibrils formed from the yeast protein Sup35NM as scaffold. Amyloid fibrils are a type of protein structures with a characteristic fibrous shape. Some amyloid fibrils are well-known to be associated with diseases such as Alzheimer's disease, Parkinson's disease, and systemic amyloidosis. However, many amyloid structures are beneficial, or "functional" in that they fill essential biological roles, for example the functional amyloid protein Sup35 from Baker's yeast. Sup35 forms amyloid fibrils in yeast cells and this allows it to functions normally as a molecular switch. 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. Collaborative work in the Xue and von der Haar labs has already generated the first Sup35NM-PETase WT fusion protein, demonstrating the feasibility and the training potential of this project. In this project, the successful PhD candidate will generate new fusion proteins containing recently discovered PETase sequences with mutations that enhance their activity. They will then assemble synthetic filaments as well as meshes, and characterise the structure and the PET degrading activity of the materials made.