| Project/Area Number |
04453082
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業物理化学・複合材料
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| Research Institution | Kumamoto Uiversity |
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Principal Investigator |
TANIGUCHI Isao Kumamoto University, Faculty of Engineering, Professor, 工学部, 教授 (90112391)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Hiroko Kumamoto University, Graduate School of Science and Technology, Research Associa, 大学院・自然科学研究科, 助手 (60040424)
KIDA Kenji Kumamoto University, Faculty of Engineering, Professor, 工学部, 教授 (00195306)
NISHIYAMA Katsuhiko Kumamoto University, Faculty of Engineering, Assistant Professor, 工学部, 講師 (10202243)
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| Project Period (FY) |
1992 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1992: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | Spectroelectrochemistry / Metalloprotein / Functional Modified Electrode / Optically Transparent Electrode / Circular Dichroism / Stopped-Flow Measurement / Site-Directed Mutagenesis / Dynamics of Structural Change / マイクロ電極集合体モデル / ラマン分光法 / 合成ポリペプチド / 構造変化 / 酵素モデル金属錯体 / 蛍光スペクトル |
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| Research Abstract |
The aims of the present study are to i) prepare of optically transparent functional electrodes for Spectroelectrochemical measurements, ii) develop of new spectroelectrochemical techniques, and iii) on the basis of these developments, study on biological functions related to structural change of metalloproteins.
Preparation of functional electrodes for metalloprotein electrochemistry
We have succeeded to prepare optically transparent In_2O_3 functionalized electrodes for myoglobins and ferredoxins. The surface hydrophilicity of an In_2O_3 electrode affected very much the perk separation of the voltammogram of myoglobin, The water layr of the electrode surface may prevent from the strong adsorption of myoglobin to exclude denaturation of the protein, and also surface water would preferably take part in the redox reaction (water molecule acts as the sixth ligand of metmyoglobin). On the other hand, at positively charged polypeptide modified electrodes, for example, negatively charged ferre
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doxins showed clear voltammograms. Such surface functions as charge, hydrophilicity and strength of interaction between protein and electrode, are found to be important, but importantly the required degrees of these functions depend on the proteins and functional electrode surfaces of interest.
Development of new spectroelectrochemical techniques
Using functionalized optically transparent electrodes, in situ UV-visible, Near Infratred (NIR), circular dichroism (CD) and magnetic circular dichroism (MCD) spectroelectrochemical cells were prepared. Also, by modification of the instruments, data accumulation and automatic measurements became possible to obtain reliable and reproducible data with high S/N ratios.
Spectroelectrochemical measurements of metallopreteins
Using the developed techniques in the present study, redox reactions of cytochrome c, myoglobins, ferredoxins and their mutated molecules were examined to study in situ the dynamics of structural change during electron transfer related to biological functions of these metalloprtoteins and to monitor the bioelectrochemical reactions such as NADPH production in the presence of ferredoxin-NADP^+-reductase (FNR) using thermostable chlorella ferredoxin as a mediator. Less
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