1987 Fiscal Year Final Research Report Summary
Structure and function of photosynthetic oxygen evolution enzyme
Project/Area Number |
61540490
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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 | Kyushu University |
Principal Investigator |
YASUSI Yamamoto Department of Biology, Faculty of Science, Kyushu University, 理学部, 助手 (40091251)
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Project Period (FY) |
1986 – 1987
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Keywords | Photosynthesis / Photosystem II / Oxygen evolution / Extrinsic proteins / Mn atom / Protein purification / 葉緑体 |
Research Abstract |
Photosynthetic oxygen evolution system is closely associated with Photosystem II in chloroplasts. The oxidizing equivalents produced by the photochemical reaction of Photosystem II are accumulated in catalytic Mn atoms and water molecules coordinated with the Mn atoms are oxidized and oxygen is produced. There are three extrinsic proteins in PS II, and they participate in stabilization of Mn atoms, concentration of Cl^- and binding of Ca^<2+>. In the present study, the organization of the oxygen evolution system was studied by the following ways: 1. An efficient method was developed to purify the three extrinsic proteins from spincach PS II particles where butanol/water phase partitioning and ion-exchange chromatogrphy were employed. The molecular properties of the proteins including N-terminal amino acid sequence were studied with the purified proteins. 2. Organization of the oxygen evolution system was studied by butanol/water phase partitioning of the spinach PS II particles. 3. The amount and stability of the extrinsic 33-kDa protein were studied with thylakoid membranes of Chlamydomonas reinhardi which was grown under Mn-deficient condition. It was suggested from the study that Mn atoms are not involved in the binding of the extrinsic protein and PS II reaction center-binding protein, althouth they are located at the interface between the two proteins.
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