Mechanism of zinc-insertion into porphyrin ring in acidophilic photosynthetic bacteria

嗜酸光合细菌卟啉环锌插入机制

• 批准号: 12640629
• 负责人: TAKAMIYA Ken-ichiro
• 金额: $ 2.24万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640629/
• 关键词: zinc-bacteriochlorophyll; bacteriochlorophyll; acidophilic photosynthetic bacteria; magnesium-chelatase; farrochelatase; chlorophyll biosynthesis; Acidiphilium rubrum

The aim :Final aim of this research is to elucidate the mechanism of biosynthesis of zinc-bacteriochlorophyll in acidophilic photosynthetic bacteria.Results and scope :1. In Acidiphilium rubrum, there was a single copy of magnesium chelatase subunit genes and these were functional in this bacterium.2. Only magnesium-protoporphyrin IX and its monomethyl ester accumulated but not zinc-protoporphyrin IX or its monomethylester in the bacterium. Protoporphyrin IX monomethyl ester was also detected as an intermediate. These suggested magnesium was exchanged by zinc after magnesium insertion to form zinc-bacteriochlorophyll.3. Whether the exchange takes place in enzymatically or non-enzymatically could not be determined, but it was possible that in the low pH environment, where zinc-bacteriochlorophyll might be formed, the exchange take places very easily and non-enzymatically.4. We tried to detect intermediates containing zinc-tetrapyrroles in this bacterium to identify the exchange reaction but so far we could not.

目的：本研究的最终目的是阐明嗜酸性光合细菌中锌细菌叶绿素的生物合成机制。结果与范围： 1．在红色嗜酸菌中，存在单拷贝的镁螯合酶亚基基因，并且这些基因在该细菌中具有功能。2．细菌中仅积聚镁原卟啉 IX 及其单甲酯，但不积聚锌原卟啉 IX 或其单甲酯。还检测到原卟啉 IX 单甲酯作为中间体。这些表明镁插入后镁被锌交换形成锌-细菌叶绿素。3．交换是通过酶促还是非酶促无法确定，但有可能在低pH环境下，可能形成锌细菌叶绿素，交换非常容易且非酶促地发生。 4．我们试图检测这种细菌中含有四吡咯锌的中间体来鉴定交换反应，但到目前为止我们还做不到。

项目成果

Suzuki, T., Masuda, T. et al.: "Two Types of ferrochelatase in photosynthetic and non-photosynthetic tissues : their・・・・"J. Biol. Chem.. 277(in press). (2001)

Suzuki, T., Masuda, T. 等人：“光合组织和非光合组织中的两种类型的亚铁螯合酶：它们的……”J. Biol. 277（出版中）。

Masuda, T., Inoue, K. et al.: "Magnesium insertion by magnesium chelatase in the biosynthesis of zinc-bacteriochlorophyl a・・・・"J.Biol.Chem.. 274. 33594-33600 (1999)

Masuda, T., Inoue, K. 等人：“锌-细菌叶绿素 a 生物合成中通过镁螯合酶插入镁......”J.Biol.Chem.. 274. 33594-33600 (1999)

Takamiya, K., Masuda, T., Inoue, K., Masuda, M., Nagura, A., Nagayama, M., Tamaki, A., Ohta, H., Shimada, H. and Takamiya, K.: "2000 Biosynthesis of zinc-containing bacteriochlorophyll a"Porphyrins. 9(3-4). 227-233 (2000)

Takamiya, K.、Masuda, T.、Inoue, K.、Masuda, M.、Nagura, A.、Nagayama, M.、Tamaki, A.、Ohta, H.、Shimada, H. 和 Takamiya, K.：

Masuda, T., Inoue, K., Masuda, M., Nagayama, M., Tamaki, A., Ohta, H., Shimada, H., & Takamiya, K.: "Magnesium insertion by magnesium chelatase in the biosynthsis of zinc-bacteriochlorophyll a in an aerobic acidophilic bacterium Acidiphilium rubrum"J. Bio

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Suzuki, T., Masuda, T., Masuda, T., Inokuchi, H., Shimada, H., Ohta, H. & Takamiya, K.: "Overexpression, enzymatic properties and tissue localization of a ferrochelatase of cucumber"Plant Cell Physiol.. 41. 192-199 (2000)

铃木 T.、增田 T.、增田 T.、井之口 H.、岛田 H.、太田 H.