Electron Transfer Reactions of Proteins and Their Applications in Bioelectrochemistry

蛋白质的电子转移反应及其在生物电化学中的应用

基本信息

批准号：
02045033
负责人：
TANIGUCHI Isao
金额：
$ 3.46万
依托单位：
Kumamoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

In the present research project, electron transfer reactions of proteins and their applications have been studied.Electron-transfer reactions of three components (purified, deamidated and oligomeric) of cytochrome c obtained in the purification procedure have been examined at both Io_2O_3 and promoter modified electrodes to clarify the role of the purification procedure of cytochrome c for the rapid electron transfer. Promoter-modified electrodes have also been applied to study effects of origin and modification of lysine residues of cytochrome c on the electrode reaction and protein-protein interactions.Myoglobin (from horse heat, Mb) has found to show a stable redox wave at a clean In_2O_3 electrode, for the first time. The heterogeneous electron-transfer rate constant(k^<O'>)depended on the pH of the solution, and >3 x 10^<-4> cm/s was obtained at pH 6.5 as the best value. The largest k^<O'> value was again observed for sperm whale Mb at pH 6.5 independent of the pI values of Mb used(horse heart : 6.8, sperm whale : 8.25).For ferredoxin (from spinach and maize, Fd), well-defined redox wave was found to be observed at functional electrodes in the presence of small amounts of polycations, such as poly-L-lysine and poly-L-ornithine. The k^<O'> value was estimated to be >5 x 10^<-3> cm/s. The redox wave was stable in the pH 6 to 10 region. Electrochemistry of Fd was applied to develop bioelectrochemical systems using Fd as an electron-donating mediator for suitable enzyme reactions as in the photosynthetic systems in nature.Also, in the present research project, new spectroelectrochemical techniques have been developed and applied to study the electron transfer reactions of biological molecules, and a model of cell membrane having a function of electron transport was developed using a Meldola's blue incorporated decanethiol modified gold electrode..

在本研究项目中，研究了蛋白质的电子转移反应及其应用。在Io_2O_3和启动子修饰电极上检查了纯化过程中获得的细胞色素c的三种成分（纯化的、脱酰胺的和寡聚的）的电子转移反应阐明细胞色素 c 纯化程序对快速电子转移的作用。启动子修饰电极也已用于研究细胞色素 c 赖氨酸残基的起源和修饰对电极反应和蛋白质-蛋白质相互作用的影响。肌红蛋白（来自马热，Mb）已被发现在干净的条件下表现出稳定的氧化还原波。 In_2O_3电极，首次。异质电子转移速率常数(k^<O'>)取决于溶液的pH值，并且在pH 6.5时获得>3×10^-4cm/s作为最佳值。再次在 pH 6.5 时观察到抹香鲸 Mb 的最大 k^<O'> 值，与所用 Mb 的 pI 值无关（马心：6.8，抹香鲸：8.25）。对于铁氧还蛋白（来自菠菜和玉米，Fd），发现在存在少量聚阳离子（例如聚-L-赖氨酸和聚-L-鸟氨酸）的情况下，在功能电极上观察到明确的氧化还原波。 k^<O'>值估计为>5×10^-3cm/s。氧化还原波在pH 6至10范围内稳定。 Fd 的电化学被应用于开发生物电化学系统，使用 Fd 作为供电子介体进行合适的酶反应，如自然界中的光合作用系统。此外，在本研究项目中，还开发了新的光谱电化学技术并应用于研究电子转移利用Meldola蓝掺入癸硫醇修饰金电极开发了具有电子传递功能的细胞膜模型。