基于生物大分子自组装的光合仿生[FeFe]-氢化酶研究

通过光催化方法制造氢气在绿色能源和疾病治疗领域有重要应用价值。铁硫簇单元是天然[FeFe]氢化酶关键的光化学反应中心，生理条件下拥有极强的催化质子还原的能力，但在体外易失活，其活性和稳定性强烈依赖于蛋白质微环境。围绕铁硫簇反应中心的微环境，本项目拟解决两个科学问题：1）如何应用多肽冠来保护氢化酶模拟物免于暴露于外界环境？2）DNA双链能否介导光敏剂与氢化酶模拟物的电子传递并增强催化析氢活性？本项目研究内容主要包括：1）以铁蛋白多肽为冠、氢化酶模拟物为壳、二氧化钛为核，评估铁蛋白多肽冠在对光化学反应中心的保护作用及对光化学析氢性能的影响；2）将光敏剂钌多吡啶配合物和氢化酶模拟物结合到DNA双链，研究DNA双链在仿生光系统中对光诱导电子传递的作用，并以此为基础构建更复杂的氢化酶模拟体系。本项目基于生物大分子和超分子自组装原理构造的光合仿生氢化酶体系将为氢气的生物应用提供重要手段。

Photocatalytic hydrogen generation plays a vital role in green energy and disease therapy. As a key photo reaction center of natural [FeFe]-hydrogenase, the iron sulfur unit has very strong capability to catalyze proton reduction under physiological conditions. However, the natural catalyst is unstable and deactivates if isolated. The activity and stability are highly dependent on the protein microenvironment. Focusing on the microenvironment of iron sulfur reaction center, this project plans to resolve two problems: 1) How to take advantage of peptide corona to protect the iron sulfur unit, acting as a hydrogenase mimic, from exposure to exterior environment, and 2) Can DNA duplex mediate long range electron transfer between photosensitizers and hydrogenase mimic to enhance photocatalytic hydrogen generation? This project includes two main objectives: 1) Establish a new artificial photosystem containing apoferritin peptide corona, hydrogenase mimic shell and TiO2 core and evaluate the roles of peptide corona in protection of photochemical reaction center and modulation of photocatalytic hydrogen production; 2) Investigate the roles of DNA duplex in the photoinduced electron transfer in the photosystem formed by binding photosensitizer ruthenium polypyridyl complexes and hydrogenase mimic to DNA duplex, which plays a foundation to construct higher hierarchical hydrogenase mimicking systems. The artificial photosynthetic hydrogenases designed in this project, based on biomacromolecules and principles of supramolecular self-assembly, will provide an important tool for bioapplication of hydrogen.