Studies on Factors for Controlling Electron Transfer Reactions and Biological Functions of Metalloproteins Using Functional Electrode Surfaces

在本研究中，使用表面修饰的单晶金电极和其他功能化电极，考察了金属蛋白的电子转移反应和生物功能。以耐热的小球藻铁氧还蛋白作为酶的电子传递介质，制备了将酶和铁氧还蛋白共固定在多肽薄膜上的人工光合作用电极。通过扫描隧道显微镜、表面增强红外吸收光谱、表面增强拉曼光谱、阻抗测量、接触角测量、电化学还原脱附等手段，从分子水平上研究了2-、3-、4-吡啶硫醇和2，2‘、5，5’-嘧啶硫醇自组装膜修饰的功能电极表面对金属蛋白电子转移反应的结构和功能。2-PYSH修饰电极为p(4x[平方根]7R-40.9°)结构，不形成二聚体。3-PYSH呈p(6x[平方根]3R-30°)结构。在Au(100)表面也观察到了类似的结构。观察到的细胞色素c的电化学反应可以用观察到的修饰电极的结构来解释。然而，快速电子转移所需表面的性质取决于所使用的金属蛋白。利用高亲水性的In_2O_3电极表面，研究了天然肌红蛋白和重组肌红蛋白在轻水和重水中的生物功能和电子传递动力学。肌红蛋白的电子转移反应速率与血红素的卟啉骨架、氧化还原中心的金属离子类型、配位结构等有关，生物功能依赖于血红素的结构。还制备了具有比天然肌红蛋白更好生物学功能的新型重组肌红蛋白分子。制备了一种新型的人工血红素结合多肽，并将其修饰在电极表面，实现了类似金属蛋白的电子转移反应。较少

In the present study, using surface modified single crystal gold electrodes and other functionalized electrodes, electron transfer reactions and biological functions of metalloproteins have been examined.1. Using thermo-stable Chlorella ferredoxin as an electron transfer mediator of enzyme, artificial photosynthetic electrodes, on which enzyme and ferredoxin were co-immobilized in poly-peptide thin films, were prepared.2. Functional electrode surfaces modified with SAMs of 2-, 3-, and 4-pyridinethiols and 2,2' and 5,5' pyrimidinethiols were examined at molecular level to understand their structures and functions for electron transfer reactions of metalloproteins by STM, surface-enhanced IR absorption spectroscopy (SEIRAS), surface-enhanced Raman spectroscopy (SERS), impedance measurement, contact angle measurement, the electrochemical reductive desorption technique, etc. On the Au(111) surface, for example, adsorbed 4 pyridinethiol (4-PySH) showed the rectangular unit cell of p(5 x 【sq … More uare root】3R-30°) structure with an interaction of two neighboring 4-PySH, while the 2-PySH modified electrode showed a p(4 x 【square root】7R-40.9°) structure with no dimer formation. 3-PySH showed a p(6 x 【square root】3R-30°) structure. Similar structures were also observed on the Au(100) surface. The observed electrochemical response of cytochrome c can be explained in terms of the observed structures of modified electrodes. However, properties of the surfaces required for the rapid electron transfer depended on metalloproteins used.3. Using highly hydrophilic surface of In2O3 electrodes, biological functions and electron transfer kinetics of native and reconstituted myoglobins were examined in light and heavy water. The rates of electron transfer reactions of myoglobins were related to the porphyrin backbone of the heme, type of metal ion of the redox center, coordination structure etc. Biological functions depended on heme structures. New reconstituted myoglobin molecules having biological functions better than native myoglobin were also prepared.4. A new artificial heme-incorporated polypeptide was prepared, and modified on the electrode surface to give electron-transfer reactions similar to a metalloprotein. Less