Roles of Ca2+ in uphill energy transfer of purple photosynthetic bacteria

• Project/Area Number: 16K07295
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional biochemistry
• Research Institution: Kobe University
• Principal Investigator: KIMURA YUKIHIRO 神戸大学, 農学研究科, 准教授 (20321755)
• Research Collaborator: Otomo Seiu ; Akimoto Seiji
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 光合成細菌 / 光捕集タンパク質 / uphill型エネルギー移動 / カルシウム / 赤外分光法 / ラマン分光法 / 超高速分光法 / 熱量分析 / 金属タンパク質 / 光合成

Outline of Final Research Achievements

Thermophilic purple sulfur bacteirum Thermochromatium tepidum exhibits its light-harvesting 1 (LH1) Qy absorption at 915 nm in the near-infrared region. The LH1 complex transfers the low light energy into a reaction center (RC) against the energy barrier (uphill energy transfer) to initiate the photosynthetic charge separation. Interestingly, Ca2+ is a possible factor to be involved in this uphill energy transfer to function as a binder of the RC and a redox-active C-subunit. The binding of the C-subunit to the RC results in the lowering of the Qy transition energy of the special pair to enable the uphill enrgy transfer smoothly.

Academic Significance and Societal Importance of the Research Achievements

近赤外光は地球に降り注ぐ太陽光の約4割を占める未利用のエネルギー資源である。水は低きに流れるが、紅色光合成細菌は低エネルギーの近赤外光をより高いエネルギーに変換（uphillエネルギー移動）して有効なエネルギー源をつくり出している。本研究では、紅色細菌の中でもより低い近赤外光を利用可能な菌に着目し、この種がCaを利用して色素分子の配向状態を制御し、低エネルギー吸収を可能にしていること、およびuphillエネルギーギャップを小さくしていることを明らかにした。本研究で得られた知見は、学術的な意義も大きいが、近赤外光応答型人工光合成による新しいエネルギー資源の創出へとつながる可能性を秘めている。

Research Products

• [Int'l Joint Research] 南イリノイ大学(米国)
• [Int'l Joint Research] Southern Illinois Universty(U.S.A.)
• [Int'l Joint Research] Southern Illinois University(米国)
• [Journal Article] Biochemical and Spectroscopic Characterizations of a Hybrid Light-Harvesting Reaction Center Core Complex (2018)
  • Author(s): Kimura Yukihiro、Hashimoto Kanako、Akimoto Seiji、Takenouchi Mizuki、Suzuki Kengo、Kishi Rikako、Imanishi Michie、Takenaka Shinji、Madigan Michael T.、Nagashima Kenji V. P.、Wang-Otomo Zheng-Yu
  • Journal Title: Biochemistry Volume: 57 Issue: 30 Pages: 4496-4503
  • DOI: 10.1021/acs.biochem.8b00644
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] C-Terminal Cleavage of the LH1 a-Polypeptide in the Sr2+-Cultured Thermochromatium tepidum (2018)
  • Author(s): Y Kimura, Y.*, Kawakami, T., Arikawa, T., Yong Li, Yu, L.-J., Ohno, T., Madigan, M.T., and Wang-Otomo, Z.-Y.
  • Journal Title: Photosynth. Res Volume: 135 Issue: 1-3 Pages: 23-31
  • DOI: 10.1007/s11120-017-0393-8
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Probing Structure-Function Relationships in Early Events in Photosynthesis Using a Chimeric Photocomplex (2017)
  • Author(s): Nagashima, V. P. K., Sasaki, M., Hashimoto, K., Takaichi, S., Nagashima, S., Yu, L.-J, Abe, Y., Goto, K., Kawakami, T., Takenouchi, M., Shibuya, S., Yamaguchi, A., Ohno, T., Shen, J.-R., Inoue, K., Madigan, M.T., Kimura, Y.* and Wang-Otomo, Z.-Y.
  • Journal Title: Proc. Nat. Aca. Sci. Volume: 114 Issue: 41 Pages: 10906-10911
  • DOI: 10.1073/pnas.1703584114
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effects of Calcium Ions on the Thermostability and Spectroscopic Properties of the LH1-RC complex from a New Thermophilic Purple Bacterium Allochromatium tepidum (2017)
  • Author(s): Kimura, Y.*, Lyu, S., Okoshi, A., Okazaki, K., Nakamura, N., Ohashi, A., Ohno, T., Kobayashi, M., Imanishi, M., Takaichi, S., Madigan, M. T., Wang-Otomo, Z.-Y.
  • Journal Title: J. Phys. Chem. B Volume: 121 Issue: 19 Pages: 5025-5032
  • DOI: 10.1021/acs.jpcb.7b03341
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spectroscopic and Thermodynamic Characterization of the Metal-Binding Sites in the LH1-RC Complex from Thermophilic Photosynthetic Bacterium Thermochromatium tepidum (2016)
  • Author(s): Kimura, Y.*, Yura, Y., Hayashi, Y., Yong Li, Onoda, M., Yu, L.-J., Wang-Otomo, Z.-Y., Ohno, T.
  • Journal Title: J. Phys. Chem. B Volume: 120 Issue: 49 Pages: 12466-12473
  • DOI: 10.1021/acs.jpcb.6b10068
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Structure Basis for the Unusual Qy Red-shift and Enhanced Thermostability of the LH1 Complex from Thermochromatium tepidum (2016)
  • Author(s): Yu, L.-J., Kawakami, T., Kimura, Y., and Wang-Otomo, Z.-Y.
  • Journal Title: Biochemistry Volume: 55 Issue: 47 Pages: 6495-6504
  • DOI: 10.1021/acs.biochem.6b00742
  • Peer Reviewed
• [Presentation] Where is the quinone gate in purple photosynthetic bacterial LH1-RC complex? (2018)
  • Author(s): Wang-Otomo, Z.-Y., and Kimura, Y.
  • Organizer: The 56th Annual Meeting of the BSJ
• [Presentation] Origin of the anomalous uphill energy gap in the light-harvesting reaction center from purple photosynthetic bacterium strain 970 (2018)
  • Author(s): Imanishi, M., Kobayashi, M., Takenaka, S., Madigan, M.T., Wang-Otomo, Z.-Y., and Kimura, Y.
  • Organizer: The 56th Annual Meeting of the BSJ
• [Presentation] Light-induced FTIR spectroscopic studies on quinone exchange mechanism of the LH1-RC complexes from native and chimeric purple bacteria (2018)
  • Author(s): Kishi, R., Imanishi, M., Hashimoto, K., Nagashima, V.P.K., Kobayashi, M., Takenaka, S., Wang-Otomo, Z.-Y., and Kimura, Y.
  • Organizer: The 56th Annual Meeting of the BSJ
• [Presentation] 紅色光合成細菌Thiorhodovibrio Strain 970が示す異常なLH1 Qyレッドシフトの起源 (2018)
  • Author(s): 今西三千絵、竹之内瑞貴、小林正幸、竹中慎治、M.T. Madigan、J. Overmann、大友征宇、木村行宏
  • Organizer: 第26回光合成セミナー
• [Presentation] 同位体標識化された好熱性紅色硫黄細菌由来LH1-RC複合体の振動分光学的解析 (2018)
  • Author(s): 木村行宏、今西三千絵、永麗、大野隆、中川支央里、佐賀佳央、M.T. Madigan、大友征宇
  • Organizer: 第26回光合成セミナー
• [Presentation] 光誘起FTIR分光法を用いた紅色細菌由来LH1-RC複合体におけるキノン分子の追跡 (2018)
  • Author(s): 岸利華子、今西三千絵、小林正幸、永島賢治、竹中慎治、M.T. Madigan、大友征宇、木村行宏
  • Organizer: 第26回光合成セミナー
• [Presentation] 好熱性および好塩性を示すHalorhodospira halochloris由来光捕集反応中心複合体の特性解析 (2018)
  • Author(s): 能島紳吾、小林正幸、竹中慎治、M.T. Madigan、大友征宇、木村行宏
  • Organizer: 第26回光合成セミナー
• [Presentation] 963 nmにQy遷移をもつ紅色細菌Thiorhodovibrio strain 970由来LH1-RCの特性評価 (2018)
  • Author(s): 竹之内瑞貴、川上知朗、高市真一、木村行宏, M.T. Madigan、J. Overmann、大友征宇
  • Organizer: 第9回日本光合成学会
• [Presentation] FTIR 分光法を用いた好熱性紅色細菌 Thermochromatium tepidumにおける光合成電子伝達反応のモニタリング (2017)
  • Author(s): 今西三千絵,橋本佳奈子,永島賢治,小林正幸,由良優季,大野隆,大友征宇,木村行宏
  • Organizer: 第58回日本植物生理学会年会
  • Place of Presentation: 鹿児島大学（鹿児島県・鹿児島市）
  • Year and Date: 2017-03-16
• [Presentation] Spectroscopic and thermodynamic analyses of the LH1-RC complexes from a new thermophilic purple bacterium Allochromatium tepidum (2017)
  • Author(s): Lyu, S., Imanishi, M., Nojima, S., Kobayashi, M., Ohno, T., Wang-Otomo, Z.-Y., and Kimura, Y.
  • Organizer: 5th Awaji International Workshop on Electron Spin Science & Technology
  • Int'l Joint Research / Invited
• [Presentation] Monitoring of quinone reduction in the thermophilic purple bacterium Thermochromatium tedium by means of isotope-edited FTIR spectroscopy (2017)
  • Author(s): Imanishi, M., Kishi, R., Kobayashi, M., Wang-Otomo, Z.-Y., and Kimura, Y.
  • Organizer: The 55th Annual Meeting of the BSJ
• [Presentation] Co-crystallization of a bacterial photosynthetic electron-transfer complex (2017)
  • Author(s): Kawakami, T., Liang, T., Okazaki, K., Kimura, Y., and Otomo, S.
  • Organizer: he 55th Annual Meeting of the BSJ
• [Presentation] Thermochromatium tepidumおよびRhodobacter sphaeroides由来LH1-RCキメラ複合体の特性解析 (2017)
  • Author(s): 木村行宏、秋本誠志、今西三千絵、岸利華子、橋本佳奈子、大野隆、永島賢治、大友征宇
  • Organizer: 第25回光合成セミナー：反応中心と色素系の多様性
• [Presentation] 同位体標識化された好熱性紅色細菌Thermochromatium tediumにおけるキノール分子の振動分光学的検出 (2017)
  • Author(s): 岸利華子、今西三千絵、小林正幸、大野隆、大友征宇、木村行宏
  • Organizer: 第25回光合成セミナー：反応中心と色素系の多様性
• [Presentation] 新規好熱性紅色細菌Allochromatium tepidum由来LH1-RC複合体におけるCa依存型耐熱化機構のATR-FTIR分析 (2017)
  • Author(s): 能島伸吾、今西三千絵、呂淑文、小林愛実、大野隆、大友征宇、木村行宏
  • Organizer: 第25回光合成セミナー：反応中心と色素系の多様性
• [Presentation] Spectroscopic and thermodynamic characterization of LH1-RC complexes from Thermophilic purple bacteria (2017)
  • Author(s): Kimura, Y.
  • Organizer: 8th OCARINA International Symposium
  • Place of Presentation: 大阪市立大学（大阪府・大阪市）
  • Int'l Joint Research / Invited
• [Presentation] Functional and structural roles of calcium ion in the reaction center complex from thermophilic purple photosynthetic bacterium, Thermochromatium tepidum (2016)
  • Author(s): Imanishi, M., Kobayashi, M., Kobayashi, M., Matsuzaki, M., Yura, Y., Ohno T., Wang, Z.-Y., and Kimura, Y.
  • Organizer: The 54th Annual Meeting of the BSJ
  • Place of Presentation: つくば国際会議場（茨城県・つくば市）
  • Year and Date: 2016-11-25
• [Presentation] Spectroscopic characterization of site-directed mutants in light-harvesting 1 complex from Thermochromatium tepidum (2016)
  • Author(s): Hashimoto, K., Nagashima, V.P.K., Akimoto, S., Ohno T., Wang, Z.-Y., and Kimura, Y.
  • Organizer: Annual Meeting of the BSJ
  • Place of Presentation: つくば国際会議場（茨城県・つくば市）
  • Year and Date: 2016-11-25
• [Presentation] Spectroscopic and thermodynamic characterization of the metal-binding sites in the LH1-RC complex from thermophilic purple sulfur bacterium Thermochromatium tepidum (2016)
  • Author(s): Kimura, Y., Yura, Y., Hayashi, Y.,Yong Li, Onoda, M., Wang-Otomo, Z.-Y., and Ohno T.
  • Organizer: 17th International Congress on Photosynthesis
  • Place of Presentation: Maastricht(The Netherlands)
  • Year and Date: 2016-08-07
  • Int'l Joint Research
• [Presentation] 新規好熱性紅色硫黄細菌Allochromatium tepidum由来LH1-RCの特性解析 (2016)
  • Author(s): 呂淑文、木村行宏、大野隆、M.T. Madigan、大友征宇
  • Organizer: 第24回光合成セミナー：反応中心と色素系の多様性
  • Place of Presentation: 龍谷大学（京都府・京都市）
  • Year and Date: 2016-07-09
• [Presentation] Effects of metal cations on charge separated states of the reaction center from thermophilic purple photosynthetic bacterium Thermochromatium tepidum (2016)
  • Author(s): Kimura, Y., Matsuzaki, M., Yura, Y., Wang-Otomo, Z.-Y., and Ohno T.
  • Organizer: The 4th Awaji International Workshop on Electron Spin Science & Technology
  • Place of Presentation: 淡路夢舞台国際会議場（兵庫県・淡路市）
  • Year and Date: 2016-06-19
  • Int'l Joint Research
• [Presentation] ヘテロ複合体発現系を用いたuphill型光合成反応機構の解析 (2016)
  • Author(s): 橋本佳奈子、秋本誠志、永島賢治、大友征宇、木村行宏、大野隆
  • Organizer: 第497回日本農芸化学会関西支部講演会
  • Place of Presentation: 神戸大学（兵庫県・神戸市）
• [Presentation] 新規好熱性紅色光合成細菌Allochromatium tepidum由来LH1-RCの耐熱性制御機構 (2016)
  • Author(s): 呂淑文、大友征宇、M.T. Madigan、木村行宏、大野隆
  • Organizer: 第497回日本農芸化学会関西支部講演会
  • Place of Presentation: 神戸大学（兵庫県・神戸市）
• [Remarks]
  • URL: http://www.edu.kobe-u.ac.jp/ans-bpc/