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Study of exotic chlorophylls in photosynthesis

Research Project

Project/Area Number 10650804
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 工業物理化学
Research InstitutionUniversity of Tsukuba

Principal Investigator

KOBAYASHI Masami  University of Tsukuba, Institute of Materials Science, Associate Professor, 物質工学系, 助教授 (70234846)

Project Period (FY) 1998 – 1999
Project Status Completed (Fiscal Year 1999)
Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1999: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1998: ¥1,900,000 (Direct Cost: ¥1,900,000)
KeywordsPhotosynthesis / LH1 / Bacteriochlorophyll / Reaction center / chlorophyll / Purple bacteria / 亜鉛バクテリオクロロフィル / 好酸性バクテリア / Acidiphilium rubrum
Research Abstract

We found a novel Zn-containing bacteriochlorophyll in an aerobic bacterium Acidiphilium rubrum growing under acidic conditions. We have unambiguously determined the molecular structure of this pigment by HPLC, optical spectroscopy, circular dichroism, fast atom bombardment mass spectrometry and ィイD11ィエD1H-NMR measurements. The structure of the pigment was confirmed to be identical to that of bacteriochlorophyll a esterified with phytol, except that the central metal is zinc (Zn) instead of magnesium (Mg).
The major pigments of both antenna systems and reaction centers (RCs) are chlorophylls (Chls) in higher plants and bacteriochlorophylls (BChls) in photosynthetic bacteria. Chls and BChls have been unquestionedly believed to be Mg complexes of substituted chlorin or bacteriochlorin macrocycles, with a sole exception of metal-free Chl a and BChl a, called Phe a and BPhe a, that act as primary electron acceptors in photosystem 2 of higher plants and in the RC of purple bacteria. However, we found a novel BChl a containing Zn as the central metal in an aerobic bacterium Acidiphilium rubrum growing under low pH. We discussed the reason for the choice of Zn as the central metal in A. rubrum, referring to such physicochemical behaviors of Zn-BChl a as the spectroscopic and redox properties.
Zn-BChl a from Acidiphilium rubrum was compared with the normal BChl a from Rhodobacter sphaeroides for the pheophytinization (de-metalation) rate in aqueous acetone containing HCl. Zn-BChl a was pheophytinized roughly 10ィイD16ィエD1-fold more slowly than BChl a. The high resistance of Zn-BChl a to acid may be one of the reasons why A. rubrum, living in media of low pH, chose Zn instead of Mg as the central metal.

Report

(3 results)
  • 1999 Annual Research Report   Final Research Report Summary
  • 1998 Annual Research Report
  • Research Products

    (21 results)

All Other

All Publications (21 results)

  • [Publications] M.Kobayashi: "Exotic chlorophylls as key components of photosynthesis"Current Topics in Plant Biology. 1. 17-35 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M.Kobayashi: "Comparison of physicochemical properties of metal lochlorophylls and metallobacteriochlorophylls"Zeitschrift Physikalische Chemie. 213. 207-214 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M.Akiyama: "Stoichiometries of LHI/RC determined by the molar ratio of BCh1/BPhe analyzed by HPLC in seven species of purple bacteria containing LHI only"Photomed. Photobiol.. 21. 105-110 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M.Akiyama: "Accumulation of poly-β-hydroxybutyrate in an acidophilic photosynthetic purple bacterium Acidiphilium rubrum"Photomed. Photobiol.. 21. 101-104 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M.Kobayashi: "The primary electron acceptor of green sulfer bacteria, bacteriochlorophyll 663, is chlorophyll a esterified with △2, 6-phytadienol"Photosynth. Res.. (in press). (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M. Kobayashi: "Exotic chlorophylls as key components of photosynthesis"Current Topics in Plant Biology. 1. 17-35 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M. Kobayashi: "Comparison of physicochemical properties of metallo-bacteriochlorophylls and metallochlorophylls"Zeitschrift Physikalische Chemie. 213. 207-214 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M. Akiyama: "Stoichiometries of LH1/RC determined by the molar ratio of BChl/BPhe analyzed by HPLC in seven species of purple bacteria containing LH1 only"Photomed. Photobiol.. 21. 105-110 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M. Akiyama: "Accumulation of poly-β-hydroxybutyrate in an acidophilic photosynthetic purple bacterium Acidiphilium rubrum"Photomed. Photobiol.. 21. 101-104 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M. Kobayashi: "The primary electron acceptor of green sulfur bacteria, bacteriochlorophyll 663, is chlorophyll a esterified with △2,6-phytadienol"Photosynth. Res.. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] M.Kobayashi: "Exotic chlorophylls as key components of photosynthesis"Current Topics in Plant Biology. 1. 17-35 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] M.Kobayashi: "Comparison of physicochemical properties of metallochlorophylls and metallobacteriochlorophylls"Zeitschrift Physikalische Chemie. 213. 207-214 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] M.Akiyama: "Stoichiometrles of LH1/RC determined by the molar ratio of BCh1/Bpphe analyzed by HPLC in seven species of purple bacteria containing LH1 only"Photomed.Photobiol.. 21. 43-48 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] M.Akiyama: "Accumlation of poly-β-hydroxybutyate in an acidophilic photosynthetic purple bacterium Acidiphilium rubrum"Photomed.Photobiol.. 21. 52-55 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] M.Kobayashi: "The primary electron acceptor of green sulfur bacteria,bacterio-chlorophyll 663,is chlorophyll a esterified with △2,6-phytadienol"Photosynth.Res.. (in press.). (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] M.Kobayashi: "Structural determination of the novel Zn-containing bacteriochlorophyll in Acidiphilium rubrum" Photomed.Photobiol.20. 57-62 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] 小林 正美: "金属置換クロロフィルの物理化学" 蛋白質核酸酵素. 43・1. 75-79 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] M.Kobayashi: "Acid resistance of Zn-Bacteriochlorophyll a from an Acidophilic Bacterium Acidiphilium rubrum" Anal.Sci.14. 1149-1152 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] M.Kobayashi: "Light-independent isomerization of bacteriochlorophyll g to chlorophyll a catalyzed by weak acid in vitro" Anal.Chim.Acta. 365. 199-203 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] M.Kobayashi: "Successfully controlled isomerization and pheophytinization of bacteriochlorophyll b by weak acid in the dark in vitro" Anal.Chim.Acta. 361. 285-290 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] M.Akiyama: "Pigment composition of the reaction center complex isolated from an acidophilic bacterium Acidiphilium rubrum grown at pH 3.5" Photomed.Photobiol.20. 63-65 (1998)

    • Related Report
      1998 Annual Research Report

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Published: 1998-04-01   Modified: 2016-04-21  

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