Molecular arrangement of NADP-photoreducing system in chloroplasts.
Project/Area Number |
63540532
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
植物生理学
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Research Institution | Kobe University |
Principal Investigator |
SHIN Masateru Kobe Univ.Faculty of Science, Associate Prof., 理学部, 助教授 (50071402)
|
Project Period (FY) |
1988 – 1989
|
Project Status |
Completed (Fiscal Year 1989)
|
Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥1,600,000 (Direct Cost: ¥1,600,000)
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Keywords | chloroplast / ferredoxin-NADP reductase / FNR-L / FNR-S / NADP photoreducing activity / photosystem I particle / Thylakoids / フェレドキシンーNADP還元酵素 / 分子構築 |
Research Abstract |
Two molecular forms of ferredoxin-NADP reductase (FNR), small from (FNR-S) and large form (FNR-L), have been known to exist in chloroplasts. When spinach chloroplasts were incubated in a dilute Tris-HCl buffer at neutral pH, almost all FNR-L was easily released from thylakoids within 1 hour. Rebinding of FNR-L to the FNR-L-removed thylakoids markedly restored its NADP photoreducing activity. Restoration of the activity by rebinding of FNR-S was considerably small, suggesting that FNR-S does not participate in the NADP photoreducing reaction on the surface of thylakoids. It was concluded that FNR-L was located on the surface of thylakoids to constitute an NADP reductase complex to reduce NADP in the non-cyclic electron flow. FNR-S remained in thylakoids after extraction of FNR-L, suggesting that this FNR is located in some internal part of thylakoids. It was found to be associated with photosystem I particles. It seems that FNR-S functions as a ferredoxin-plastoquinone reductase in the cyclic electron flow, but not as an NADP reductase in the non-cyclic electron flow.
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Report
(3 results)
Research Products
(7 results)