Investigating The Effects Of Cyclisation On A Protein Tool And A Biocatalyst

植物和其他光合生物的光合作用效率很高，每年产生数十亿吨生物质。在这个物理化学过程中，太阳光被空间和能量组织的触角捕获，光捕获色素如叶绿素。一旦被捕获，能量被转移到光系统I和II中的反应中心，在那里它被转换并以化学键的形式储存。非常期望收获太阳能并生产设计的化学品和/或清洁燃料。这个博士项目的灵感来自自然，旨在采用化学生物学和有机化学技术将卷曲螺旋蛋白质折纸（CCPO）笼转化为人工光合系统，以供未来应用。在CCPO中，单个蛋白质链沿着欧拉轨迹沿着折叠成三维形状，例如多面体。多面体的侧面由卷曲螺旋（CC）二聚体片段形成，所述卷曲螺旋（CC）二聚体片段由以平行或反平行取向配对的两个α-螺旋组成。将CCPO笼转化为人工光合系统的第一步将涉及在蛋白质笼的边缘上引入受体位点。这些受体位点将用于通过同时的动态共价反应如二硫化物交换、硼酸盐和酰基肼形成来掺入触角。类似于天然光合系统，这些并入的发色团将具有明确定义的距离和取向，以允许可见光吸收和转换的最大效率。天线收集的可见光能量将用于通过加入反应中心催化生产有价值的化学品。总之，将CCPO笼转化为可见光收集系统将是朝着开发高效人工光合系统的重要一步，该系统可以以清洁和高效的方式产生有价值的化学物质。从长远来看，它推进了能够利用太阳能作为可再生能源的巨大潜力的现有技术。

Photosynthesis by plants and other photosynthetic organisms is highly efficient contributing billions of tonnes of biomass every year. In this physiochemical process, sunlight is captured by spatially and energetically organised antennae, light harvesting pigments such as chlorophyll. Once captured the energy is transferred to reaction centres in photosystems I and II where it is converted and stored in the form of chemical bonds. It is greatly desired to harvest solar energy and produce designed chemicals and/or clean fuels. Taking inspiration from Nature, this PhD project aims to employ chemical biology and organic chemistry techniques to convert a coiled-coil protein origami (CCPO) cage into an artificial photosynthetic system for future applications. In CCPO, a single protein chain is folded along a Eulerian trail into a three-dimensional shape such as a polyhedron. The sides of the polyhedron are formed from coiled-coil (CC) dimer segments, composed of two alpha-helixes which are paired in either a parallel or antiparallel orientation. The first step in the conversion of a CCPO cage into an artificial photosynthetic system will involve the introduction of receptor sites onto the edges of the protein cage. These receptor sites will be employed for the incorporation of antennae through simultaneous dynamic covalent reactions such as disulphide exchange, boronate and acyl hydrazine formation. Similar to the natural photosynthetic system, these incorporated chromophores will have well-defined distances and orientations to allow maximum efficiency of visible light absorption and conversion. The visible light energy harvested by the antennae will be used for the production of valuable chemicals catalysed by the incorporation of a reaction centre. In summary, conversion of CCPO cages into visible light harvesting systems will be an important step towards the development of efficient artificial photosynthetic systems which can produce valuable chemicals in a clean and efficient manner. In the long run, it advances the technologies available that are capable of utilising the huge potential of solar energy as a renewable energy resource.