| Project/Area Number |
02454013
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
植物生理学
|
|---|
| Research Institution | Okayama University |
|---|
Principal Investigator |
SATOH Kimiyuki Okayama Univ., Faculty of Science, Professor, 理学部, 教授 (10032822)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Yuichiro Okayama Univ., The Graduate School of Natural Science and Technology, Assistant, 大学院・自然科学研究科, 助手 (50183447)
山本 泰 岡山大学, 理学部, 助教授 (40091251)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Project Status |
Completed (Fiscal Year 1991)
|
| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1991: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1990: ¥3,600,000 (Direct Cost: ¥3,600,000)
|
|---|
| Keywords | Photosynthesis / Photosystem II / Reaction Center / D1 protein / Molecular Architecture / Charge Separation / Quinone / Protein Synthesis / 光化学系II反応中心 / D1蛋白質 / Pー680 / EPR / プロセシングプロテア-ゼ / 翻訳制御 / 光化学反応中心 / Cー末プロセシング / クロロフィル |
|---|
| Research Abstract |
The efficient energy transformation in the primary process of photosynthesis is ensured by the highly ordered organization of photochemical reaction centers, in physical, chemical and biological sense. In photosystem II (PSII), the primary charge separation takes place in a pigmentprotein complex consisted of D1 and D2 proteins and some other components, which has recently been isolated and the chemical and physical properties have been analyzed (Nanba and Satoh, 1987). In the present study, the organization of PSII reaction center has been analyzed in two aspects. In the first part, stoichiometries of protein subunits and of pigments and redox cofactors of the isolated reaction center have been determined. The orientation of the primary donor (P-680) has been analyzed by EPR spectroscopy and it is deduced that the triplet state is localized on a chlorophyll, the tetrapyrrolic plane of which is tilted about 30ﾟ to the membrane. In the second part, the analysis has been focussed on some aspects of light-regulated turnover of D1 subunit of the PSII reaction center, which include the mechanism of light-regulated synthesis of D1 protein in isolated chloroplasts and the characterization of an enzyme involved in the C-terminal processing of D1 precursor protein. Determination of the levels of ATP in chloroplasts and the rate of synthesis of D1 protein under various conditions suggested that the level of ATP in soluble, stromal fraction controls the synthesis of D1 protein. The enzyme involved in the processing taking place after the synthesis has been extracted and purified.
|
