1997 Fiscal Year Annual Research Report

電子移動タンパク質の構造の最適化機構

Research Project

Project/Area Number	08458214
Research Institution	Okazaki National Institute
Principal Investigator	伊藤繁岡崎国立共同研究機構, 基礎生物学研究所, 助教授 (40108634)
Keywords	光合成 / 電子移動 / 反応中心 / 光化学反応 / クロロフィル / キノン / 蛋白質 / 進化
Research Abstract	電子移動タンパク質の最適化機構を検討した。光合成反応中心、チトクロム、鉄硫黄タンパク質、キノール-チトクロムc酸化還元酵素を検討した。 1.天然タンパク質の比較。最古の光合成系ともいえる(絶対嫌気性)緑色硫黄光合成細菌の反応中心内部のクロロフィル配置、膜結合型チトクロムの反応等を明らかにして、好気性及び植物型光合成と比較し、分子機能の最適化機構を検討した。サブユニットの機能分化、内部色素数と機能の変化、遊離型へチトクロム反応への進化などを明らかにした。 2.人工化による分子最適化機構の検討。植物光化学系1反応中心内のキノンを人工物に入れ替え、緑色細菌型に近い反応エネルギー差を作りだし、反応と構造最適化機構を検討した。この反応系は、緑色細菌とは異なる温度依存性を示し、未知の最適化原理を示唆した。 3.(新しい光合成系をもつ)新型生物の発見と分子最適化機構の検討。 (1)好酸性細菌Acidiphilium(A.)rubrumが、Zn型バクテリオクロロフィルaで、光合成をすることを示した。原始光合成はZn-ポルフィリンで始まった可能性もでてきた。 (2)近赤外光(740nm)で酸素発生型光合成をする生物Acaryochloris marinaの光合成。植物及びシアノバクテリアは全て680nmの赤色光を利用して光合成をするが。このシアノバクテリア様生物はクロロフィルdを使う。このタンパク質構造最適化機構の検討を開始した。

Research Products
(12 results)

All Other

All Publications (12 results)

[Publications] 伊藤繁: "地球を変えた光合成" 日本物理学会誌. 53(2). 100-106 (1998)
[Publications] Itoh,S.et al.: "Accumulation of Fe,Cr and Ni metals inside cells of acidophilic bacterium Acidiphilium rubrum that produced Zn containing bacteriochlorophyll a." Plant and Cell Physiology. (in press.). (1998)
[Publications] Ohoka,H.et al.: "Viscosity dependence of the electron transfer rate from bound cytochrome c to P840 in the photosynthetic reaction center of a green sulfur bacterium Chlorobium tepidum." Biochemistry. 36. 9267-9272 (1997)
[Publications] Tomo,T.et al.: "Topology of pigments in the isolated photosystem II reaction center studied by selective extraction." Biochimica Biophysica Acta. 1321. 21-30 (1997)
[Publications] Dzuba,S.A.et al.: "Electron spin echo of spin-polarized radical pairs in the intact and quinone-reconstituted plant photosystem I reaction centers." Chemical Physics Letters. 264. 238-244 (1997)
[Publications] Hara,H.et al.: "The distance between P680 and Q_A in Photosystem II determined by ESEEM" Biochimica Biophysica Acta. 1322. 77-85 (1997)
[Publications] Baba,K.et al.: "Photoinhibition of photosystem I electron transfer activity in isolated photosystem I preparations with different chlorophyll contents." Photosyntesis Research. 347. 121-130 (1996)
[Publications] Iwaki,M.et al.: "ΔG^0 dependence of the electron transfer rate in photosynthetic reaction center of plant photosystem I : Natural optimization of reaction between chlorophyll a (A_0) and quinone." Journal of Physical Chemistry. 100. 10802-10809 (1996)
[Publications] Itoh,S.et al.: "Stabilization of P680^+ at 77 K in the Quinone-reconstituted Photosystem II Reaction Center (D1-D2-cytochrome b559) complex." Plant and Cell Physiology. 37. 833-839 (1996)
[Publications] Wakao,N.et al.: "Discovery of natural photosynthesis using Zn-containing bacteriochlorophyll in an aerobic bacterium Acidiphilium rubrum." Plant and Cell Physiology. 37. 889-893 (1996)
[Publications] Saeki,K.et al.: "Site-specific mutagenesis of Rhodobacter capsulatus Ferredoxin I,FdxN,that functions in nitrogen fixation." Journal of Biological Chemistry. 271. 31399-31406 (1996)
[Publications] Itoh,S.and Iwaki,M.: "Electron transfer in plant photosystem I photosynthetic reaction center containing artificial molecules." in "New challenges in Organic Chemistry" (Ed.by Osa,T.,Gordon and Breach Science Publishers,Amsterdam,Netherlands). 265-277 (1998)

1997 Fiscal Year Annual Research Report

電子移動タンパク質の構造の最適化機構

Principal Investigator

伊藤 繁 岡崎国立共同研究機構, 基礎生物学研究所, 助教授 (40108634)

Research Products

[Publications] 伊藤 繁: "地球を変えた光合成" 日本物理学会誌. 53(2). 100-106 (1998)

[Publications] Itoh,S.et al.: "Accumulation of Fe,Cr and Ni metals inside cells of acidophilic bacterium Acidiphilium rubrum that produced Zn containing bacteriochlorophyll a." Plant and Cell Physiology. (in press.). (1998)

[Publications] Ohoka,H.et al.: "Viscosity dependence of the electron transfer rate from bound cytochrome c to P840 in the photosynthetic reaction center of a green sulfur bacterium Chlorobium tepidum." Biochemistry. 36. 9267-9272 (1997)

[Publications] Tomo,T.et al.: "Topology of pigments in the isolated photosystem II reaction center studied by selective extraction." Biochimica Biophysica Acta. 1321. 21-30 (1997)

[Publications] Dzuba,S.A.et al.: "Electron spin echo of spin-polarized radical pairs in the intact and quinone-reconstituted plant photosystem I reaction centers." Chemical Physics Letters. 264. 238-244 (1997)

[Publications] Hara,H.et al.: "The distance between P680 and Q_A in Photosystem II determined by ESEEM" Biochimica Biophysica Acta. 1322. 77-85 (1997)

[Publications] Baba,K.et al.: "Photoinhibition of photosystem I electron transfer activity in isolated photosystem I preparations with different chlorophyll contents." Photosyntesis Research. 347. 121-130 (1996)

[Publications] Iwaki,M.et al.: "ΔG^0 dependence of the electron transfer rate in photosynthetic reaction center of plant photosystem I : Natural optimization of reaction between chlorophyll a (A_0) and quinone." Journal of Physical Chemistry. 100. 10802-10809 (1996)

[Publications] Itoh,S.et al.: "Stabilization of P680^+ at 77 K in the Quinone-reconstituted Photosystem II Reaction Center (D1-D2-cytochrome b559) complex." Plant and Cell Physiology. 37. 833-839 (1996)

[Publications] Wakao,N.et al.: "Discovery of natural photosynthesis using Zn-containing bacteriochlorophyll in an aerobic bacterium Acidiphilium rubrum." Plant and Cell Physiology. 37. 889-893 (1996)

[Publications] Saeki,K.et al.: "Site-specific mutagenesis of Rhodobacter capsulatus Ferredoxin I,FdxN,that functions in nitrogen fixation." Journal of Biological Chemistry. 271. 31399-31406 (1996)

[Publications] Itoh,S.and Iwaki,M.: "Electron transfer in plant photosystem I photosynthetic reaction center containing artificial molecules." in "New challenges in Organic Chemistry" (Ed.by Osa,T.,Gordon and Breach Science Publishers,Amsterdam,Netherlands). 265-277 (1998)

伊藤繁岡崎国立共同研究機構, 基礎生物学研究所, 助教授 (40108634)

[Publications] 伊藤繁: "地球を変えた光合成" 日本物理学会誌. 53(2). 100-106 (1998)