Scaffold-based Synthetic Models of Mono-Iron Hydrogenase: Structure and Dynamics

有了这个奖项，化学系的生命过程化学项目正在资助德克萨斯大学奥斯汀分校的迈克尔·罗斯教授研究铁中心在一种名为单铁氢化酶的酶中的作用。这种酶对于产甲烷菌中二氧化碳（CO2）的捕获是重要的分子，产甲烷菌是可以在例如人类肠道和湿地中发现的单细胞微生物。这些生物体在将它们生活的环境中的氢（H2）和CO2转化为甲烷方面非常有效。 相比之下，人工捕获和转化H2和CO2的方法效率要低得多。此外，虽然酶，特别是单铁氢化酶，利用地球上丰富的金属，如铁和镍，但酶的许多合成类似物利用贵金属，如铂、铱或钯。罗斯教授的研究重点是了解单铁氢化酶如何催化产甲烷菌中的化学转化，并将这种理解应用于开发与酶一样有效的人工催化剂。罗斯教授还参加了名为H2 fromH 2 O的外展计划。他与德克萨斯州中部地区的高中生互动，展示了将水分解为氢和氧的基础科学、环境影响和可能的应用，并从这一过程中获得能量。参加外展方案的学生进一步向他们的家庭和社区传播这些课程。 这有助于提高对发展可再生能源技术重要性的认识。UT奥斯汀的本科生直接参与外展工作，成为激励做研究，并追求就业机会和能源相关领域的研究生教育。可用的，铁基合成（人工）系统的分子性质不复制自然发生的系统的速度和效率。这项研究旨在了解自然系统的组成部分如何被纳入以提供增强的反应性。有三种技术方法来理解单铁氢化酶的H2活化和氢化物转移活性。首先，将合成的模型络合物与蛋白质宿主杂交，以确定蛋白质环境对模型络合物的光谱性质和功能反应性的影响（相对于独立的金属络合物）。其次，“蒽支架”的策略，用于组装的仿生fac-CNS基序修改更灵活的“蒽”支架，以研究蛋白质样的灵活性的供体臂上的模型复合物的反应性的作用。第三，复合物含有一个仿生吡啶部分，这是假设，以协助H2 heterolysis作为pendant base.This award reflects NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Prof. Michael Rose at the University of Texas at Austin to investigate the role of the iron center in an enzyme called mono-iron hydrogenase. This enzyme is molecule important for the capture of carbon dioxide (CO2) in methanogens, which are single cell microorganisms that can be found for example in the human gut and in wetlands. These organisms are very efficient at transforming dihydrogen (H2) and CO2 from the environment in which they live into methane. In contrast, artificial way to capture and transform H2 and CO2 are much less efficient. Furthermore while the enzymes, in particular mono-iron hydrogenase, utilize earth abundant metals like iron and nickel, many synthetic analogues of the enzymes utilize precious metals like platinum, iridium or palladium. The research of Professor Rose focuses on understanding how the mono-iron hydrogenase catalyzes the chemical transformation in the methanogens and applying this understanding to developing artificial catalysts as efficient as the enzyme. Professor Rose also participates in the outreach program called H2fromH2O. He interacts with high school students in the central Texas region to demonstrate the fundamental science, environmental impact and possible applications for splitting water into hydrogen and oxygen and derive energy from this process. The students who participate in the outreach program further disseminate such lessons to their families and communities. This serves to raise awareness about the importance of developing renewable energy technologies. UT Austin undergraduates directly participate in the outreach efforts, become motivate to do research, and pursue job opportunities and graduate education in energy-related fields.The available, iron-based synthetic (artificial) systems of a molecular nature do not replicate the speed and efficiency of the naturally occurring system. This research seeks to understand how components of the natural system can be incorporated to provide for enhanced reactivity. There are three technical approaches to understanding the H2-activating and hydride transfer activity of the enzyme mono-iron hydrogenase. First, synthetic model complexes are hybridized with protein hosts to determine the effect of the protein environment on the spectroscopic properties and functional reactivity of the model complexes (versus stand-alone metal complexes). Second, the "anthracene scaffold" strategy for assembling the biomimetic fac-CNS motif is modified with more flexible "anthranoid" scaffolds to investigate the role of protein-like flexibility of the donor arms on the reactivity of the model complexes. Third, the complexes contain a biomimetic pyridine moiety, which is hypothesized to assist in H2 heterolysis as a pendant base.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.