1992 Fiscal Year Final Research Report Summary
Electron Transfer Reactions of Proteins and Their Applications in Bioelectrochemistry
| Project/Area Number |
02045033
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | University-to-University Cooperative Research |
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| Research Institution | Kumamoto University |
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Principal Investigator |
TANIGUCHI Isao Kumamoto University, Professor, 工学部, 教授 (90112391)
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| Co-Investigator(Kenkyū-buntansha) |
JAN F. CHELE Virginia Commonwealth大学, 生物化学科, 教授
JAMES TURNER Virginia Commonwealth大学, 化学科, 準教授
FRED M. HAWK Virginia Commonwealth大学, 化学科, 教授
KIDA Kenji Kumamoto University, Associate Professor, 工学部, 助教授 (00195306)
SAKAKI Shigeyoshi Kumamoto University, Professor, 工学部, 教授 (20094013)
HAWKRIDGE Fred M. Virginia Commonwealth University, Professor
TURNER James Virginia Commonwealth University, Associate Professor
CHELEBOWSKI Jan F. Virginia Commonwealth University, Professor
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| Project Period (FY) |
1990 – 1992
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| Keywords | Cytochrome c / Myoglobin / Ferredoxin / Electron transfer reaction / Functional modified electrode / In situ spectroelectrochemical technique / Polypeptide / Cell membrane model |
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| Research Abstract |
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..
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