Modular design of a bioinspired tandem cell for direct solar-to-fuel conversion (Solarfueltandem)

用于直接太阳能到燃料转换的仿生串联电池的模块化设计（Solarfueltandem）

• 批准号: BB/J010294/1
• 负责人: James Barber
• 金额: $ 22.36万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FJ010294%2F1
• 关键词: Modular; design; bioinspired; tandem; cell

All fossil fuels are derived from sunlight via photosynthesis. To cope with the finite supply of fossil fuels, humanity must also learn to use sunlight to generate fuel. In nature photosystem II uses sunlight to oxidise water to oxygen, and equivalents of hydrogen, which are used to reduce CO2 to organic sugars. This difficult oxidation reaction takes place at an unusual CaMn4 metallocluster in the PSII complex, called the oxygen evolving centre (OEC). We propose to mimic the assembly of the OEC in another "scaffold" protein, by introducing variations in the side chains that will allow a metal cluster to bind. Assembling an OEC in a suitable "smart" matrix that can deal appropriately with the protons generated by water oxidation, is a crucial prerequisite to building an artificial photosynthetic system. The matrix protects the catalytic cluster from bulk solvent, controls the precise environment of the cluster, and rapidly shuttles protons from the cluster to the solvent. Preliminary scaffold designs have been made using an in-house computer program, SITEGRAFT, which searches for mutations around a site that will generate a target constellation of amino acid functional group positions. This program could also be applied to other active-site design problems. We plan on using four-helix bundle di-iron carboxylate proteins as scaffolds, as these already have a buried dimetal centre, and so should need only minor changes to accommodate a slightly larger cluster. The cluster can be assembled with chemical oxidation, and coupled to light-harvesting pigments with a charge separation motif incorporated to generate a hole with sufficient redox potential (artificial reaction centre) to drive water oxidation. Suitable pigments include zinc-porphyrins, and ruthenium bypyridine complexes. As well as this "top-down" approach, we will also investigate the incorporation of an OEC-like cluster into smaller protein maquettes, which are simpler than model proteins

所有化石燃料都是通过光合作用从阳光中获得的。为了应对化石燃料的有限供应，人类还必须学会利用阳光来生产燃料。在自然界中，光系统II利用阳光将水氧化为氧气，以及氢的等价物，后者用于将二氧化碳还原为有机糖。这一困难的氧化反应发生在PSII复合体中一个不寻常的CaMn4金属簇上，称为放氧中心(OEC)。我们建议通过在侧链中引入变异，使金属簇能够结合，来模拟OEC在另一种“支架”蛋白质中的组装。将OEC组装在合适的“智能”基质中，以适当地处理水氧化产生的质子，是建立人工光合作用系统的关键前提。该基质保护催化团簇不受主体溶剂的影响，控制团簇的精确环境，并快速将质子从团簇运送到溶剂。已经使用内部计算机程序SITEGRAFT进行了初步的支架设计，该程序搜索一个位点周围的突变，该突变将产生氨基酸功能基团位置的目标星座。该程序也可以应用于其他活动站点的设计问题。我们计划使用四螺旋束二铁羧酸盐蛋白质作为支架，因为这些蛋白质已经有一个埋藏的双金属中心，所以应该只需要很小的改变就可以适应稍微大一点的簇。该簇可以通过化学氧化进行组装，并与具有电荷分离基序的捕光颜料耦合，以生成具有足够氧化还原潜力的空穴(人工反应中心)，以驱动水氧化。合适的颜料包括锌-卟啉和Ru-吡啶络合物。除了这种“自上而下”的方法，我们还将研究在比模型蛋白质更简单的更小的蛋白质模型中加入类似OEC的簇