标题: | 重组金属乙炔苯酸紫质之人工肌红蛋白系统对于光激发电子转移机制的研究与其在生物性太阳能电池的应用 Photo-Induced Electron Transfer Study of Free-base and Metallo Carboxyphenylethynyl Porphyrins Based Artificial Myoglobin Systems and Their Biosolar Cell Application |
作者: | 胡祎庭 Hu, Yi-Ting 吴东昆 Wu, Tung-Kung 生物科技学系 |
关键字: | 肌红蛋白;金属乙炔苯酸紫质;Myoglobin;MtPE1 |
公开日期: | 2008 |
摘要: | 肌红蛋白是一个很适合用來了解光物理以及探讨光催化电子转移机制的生物系统,因为肌红蛋白的血色素基口袋可以有效稳定中间辅基的氧化或还原态。而将人工合成的辅基重组进入肌红蛋白中是一个崭新的方式为蛋白质注入新的功能。为了模拟光合作用的机转,我们设计一个更简单的系统來模拟光合作用。我们将一系列不同金属的光敏剂 metallo-5-(4-carboxy-phenylethynyl)-10,20-biphenylporphines (简称MtPE1)重组到肌红蛋白中防止自身聚集的现象以及延长在激发态的生命期。我们进行紫外光-可見光光谱、循环伏安法、萤光光谱、时间-解析萤光光谱、光化学还原法、光电流等的研究。在萤光生命期的比较,ZnPE1-Mb 以及H2PE1-Mb 在缓冲溶液中的生命期比起在有机溶剂四氢呋喃 (THF) 中的ZnPE1、H2PE1 有些微的增加。光化学还原是利用以肌红蛋白重组MtPE1 做为光敏剂,TEA做为电子提供者,NADP+为电子接受者所组成的简单系统來比较不同金属MtPE1 以及MtPE1-Mb 的转换效率。在将NADP+还原成NADPH 的效率上,以H2PE1 与ZnPE1 重组的肌红蛋白相对于只以H2PE1 与ZnPE1 为光敏剂的转换效率來說,约可提升兩倍的效率,我们推测蛋白质能有效稳定光敏剂的激发态并延长处于激发态的时间而提高转换效率。我们也利用循环伏安法确认重组之MtPE1-Mb 具有和TEA 及NADP+ 可适当转移电子的能阶。最后,也试着建构一个以MtPE1-Mb、TiO2 导电玻璃、电解液组合成能将光能转成电能的生物太阳能电池。 Myoglobin (Mb) is a suitable model to understand the photophysical properties and photoinduced electron transfer mechanism, because of the heme pocket of Mb can stabilize the reduced and oxidized state of the prosthetic group. Reconstitution of an artificial prosthetic group into apo-myoglobin (apo-Mb) is a unique method for introducing a new chemical function into the protein. To mimic the function of photosynthetic system, we design a simple system. A series of different metallo-5-(4-carboxy-phenylethynyl)-10, 20-biphenylporphines, denoted as MtPE1(used as photo-sensitizers) were reconstituted with apo-Mb to avoid self-aggregation and extend the lifetime of excited state. The photophysical properties of reconstituted Mb were examined by UV-Vis, CV, fluorescence spectra, time-resolved fluorescence spectroscopy, photochemical reduction, and photocurrent study. Fluorescence decay profiles of ZnPE1-Mb and H2PE1-Mb showed slightly increase by comparing with ZnPE1 and H2PE1 in THF. Photochemical reduction of nicotinamide adenine dinucleotide phosphate (NADP+) was studied by using MtPE1 reconstituted myoglobin (MtPE1-Mb) as a photosensitizer, and triethanolamine (TEA) as a sacrificial donor. This simple model system can let us to compare the conversion efficiency of MtPE1 and MtPE1-Mbs. H2PE1-Mb and ZnPE1-Mb exhibited 2-folds of photo-induced electron transfer efficiency than H2PE1 and ZnPE1 for converting NADP+ to NADPH. The results showed that MtPE1 reconstituted with apo-Mb can stabilize the excited state and increase the conversion efficiency. We also confirmed that MtPE1-Mb have well-matched energy level of TEA and NADP+ by CV analysis. At last, we try to combine MtPE1-Mb, TiO2 film, and electrolyte to construct a biosolar cell with solar-electric energy converting ability. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079628505 http://hdl.handle.net/11536/42710 |
显示于类别: | Thesis |
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