| Project/Area Number |
10044072
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | Yokohama National University |
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Principal Investigator |
AKUTSU Hideo YNU, Faculty of Engineering, Professor, 工学部, 教授 (60029965)
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| Co-Investigator(Kenkyū-buntansha) |
OZAWA Kiyoshi YNU, Faculty of Engineering, Research Associate, 工学部, 助手 (20251770)
FUJIWARA Toshimichi YNU, Faculty of Engineering, Associate Professor, 工学部, 助教授 (20242381)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | cytochrome cィイD23ィエD2 / tetraheme protein / Nuclear Magnetic Resonance / redox potential / over expression system / electron transfer / electron transport protein / シトクロム / Cgf C_3 / CgbC_3 / チヘムタンパク質 |
|---|
| Research Abstract |
The most remarkable characteristic of many Shewanella species is their ability to reduce insoluble metal oxides, including iron, and manganese. S. putrefaciens strain MR1 was specifically isolated as a metal oxide (iron and manganese) reducing organism, and shown to couple the reduction of metal oxides to the oxidation of organic carbon. The ability of Shewanella species to grow with a variety of different electron acceptors having redox potentials from +0.8 V (oxygen) to about 0 (elemental sulfur) implies that this bacterium is able to adjust to growth conditions through changes in the activity and/or the composition of the electron transport chain. Cytochromes are abundant in Shewanella and have been implicated in the reduction of metal oxides. The redox behavior of a tetraheme protein, cytochrome cィイD23ィエD2 was investigated in this work. The macroscopic and microscopic redox potentials were determined at pH 9. Although they are low in comparison with other cytochromes, they are higher than the redox potentials of cytochrome cィイD23ィエD2 from Desulfovibrio vulgaris Miyazaki F (DvMF). DvMF cytochrome cィイD23ィエD2 gene was successfully expressed in a facultative aerobe, Shewanella putrefaciens MR-I, under anaerobic, microaerobic, and aerobic conditions with good yields. A derivative of the broad-host-range plasmid pRK415 containing the cytochrome cィイD23ィエD2, genes from DvMF was used for transformation of S. putrefaciens MR-1, resulting in the production of holocytochrome cィイD23ィエD2 that was indistinguishable from that produced by D. vulgaris Miyazaki F.
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