1997 Fiscal Year Final Research Report Summary
Optimization mechanism of electron transfer proteins
| Project/Area Number |
08458214
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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 | Okazaki National Institute |
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Principal Investigator |
ITOH Shigeru National Institute for Basic Biology, Associate Professor, 基礎生物学研究所, 助教授 (40108634)
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| Project Period (FY) |
1996 – 1997
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| Keywords | protein / electron transfer / photosynthesis / chlorophyll / Quinone / photochemical reaction / photosynthetic bacteria / cyanobacteria |
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| Research Abstract |
Optimization mechanisms of intra-protein electron transfer were studied in four systems below. (1) plant photosystems I and II reaction centers. (2) reaction center complexes of green sulfur bacteria. (3) A new type of photosynthetic purple bacteria that uses Zn-containing bacteriochlorophylls. (4) a new type of cyanobacteria that uses chlorophyll d which absorbs far-red light, In all the photosynthetic organisms thus far known, chlorophylls are known to be essential. We, however, showed (1) proteins function to optimize the reaction environment of chlorophylls through quinone-exchange studies in the plant photosystem I and H reaction centers, (2) Zn- bacteriochlorophyll can replace the function of Mg-bacteriochlorophyll in vivo, and (3) chlorophyll d also supports the oxygenic photosynthesis as efficient as that by chlorophyll a. These results indicate that natural photosynthetic systems have more varieties than ever estimated and that the photosynthesis with new types of chlorophylls were enabled by a minor tuning of the protein structure around chlorophylls or quinones inside the reaction center protein.
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