Elucidation of the Molecular Properties of Chlorophyll a' and Its Function in Photosynthetic Reaction Centers

叶绿素a的分子性质及其在光合反应中心的功能的阐明

• 批准号: 08455391
• 负责人: WATANABE Tadashi
• 金额: $ 4.8万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455391/
• 关键词: chlorophyll a'; photosynthesis; reaction center; photosystem I; P700; HPLC; dimer; クロロフィルa′; クロロフィル; 分子間会合; 二量化; 分光特性

1. Chlorophyll a', in sharp contrast to the ordinary chlorophyll a, forms aggregates with its dimer as the building block, in aqueous alkohols and surfactant aqueous solutions. In view of the long-standing hypothesis that the PSI reaction center, P700, consists of a dimeric chlorophyll, this finding supports an idea that chlorophyll a' constitutes P700 itself.2. By use of barley and cucumber as samples, an HPLC condition has been established that can separate and identify a number of biosynthetic intermediates of chlorophyllous pigments, even for the very early phase of greening of etiolated leaves where only a miniscule amount of chlorophylls are being biosynthesized.3. The greening process of etiolated barley and cucumber has been closely examined with the above-established chromatographic technique. As a result, the relative amount of chlorophyll a' has been found to increase abruptly, in ca. 1 h after the start of greening, to a level more than twice that in mature leaves : this indicates that chlorophyll a' is indeed biosynthesized as an ingredient of the photosynthetic core pigment-protein complexes. Simultaneous examination of the amount of P700 in the course of greening yielded a stoichiometry of chlorophyll a'/P700=2 except for a very early phase, supporting the idea that this minor pigment is functioning in close association with P700.

1。叶绿素A'，与普通叶绿素A形成鲜明对比，形成二聚体作为构成块的聚集体，在水溶液和表面活性剂水溶液中。鉴于长期存在的假设是PSI反应中心P700由二聚体叶绿素组成，这一发现支持了叶绿素A''构成P700本身的想法。2。通过将大麦和黄瓜用作样品，已经建立了HPLC条件，该条件可以分离并鉴定叶绿素颜料的许多生物合成中间体，即使是在绿色叶片的绿色早期阶段，在仅在绿化的早期阶段，只有微小含量的叶绿素是生物合成的。3。在上述色谱技术中，对绿色大麦和黄瓜的绿色过程进行了仔细检查。结果，在CA中发现了相对的叶绿素a''''''叶绿素A''的量会突然增加。绿色开始后的1小时，达到成熟叶片的两倍以上：这表明叶绿素a'的确被生物合成为光合核心色素蛋白复合物的成分。除了非常早期的阶段外，在绿色过程中同时检查了P700的量，叶绿素a'/p700 = 2的化学计量法支持了这种小色素与P700密切相关的想法。

项目成果

T.Oba, T.Watanabe, M.Mimuro, M.Kobayashi, S.Yoshida: "Aggregation of Chlorophyll a' in Aqueous Methanol" Photochem.Photobiol.Vol.63, No.5. 639-648 (1996)

T.Oba、T.Watanabe、M.Mimuro、M.Kobayashi、S.Yoshida：“甲醇水溶液中叶绿素 a 的聚集” Photochem.Photobiol.Vol.63，No.5。

渡辺 正(訳): "地球環境科学入門" シュプリンガー・フェアラーク東京, 270 (1997)

Tadashi Watanabe（译者）：《地球环境科学导论》Springer Verlag Tokyo，270（1997）

M.Kobayashi, M.Akiyama, T.Watanabe, H,Kise: "Classification of Photosynthetic Reaction Centers Based on the Chlorophyll Species" Biophysics (Seibutsu-Butsuri). Vol.37, No.5 (in Japanese). 196-200 (1997)

M.Kobayashi、M.Akiyama、T.Watanabe、H、Kise：“基于叶绿素种类的光合反应中心分类”生物物理学（Seibutsu-Butsuri）。

A.Nakamura, T.Watanabe: "HPLC Determination of Photosynthetic Pigments during Greening of Etiolated Barley Leaves. Evidence for the Biosynthesis of Chlorophyll a'" FEBS Lett.(in press). (1998)

A.Nakamura、T.Watanabe：“黄化大麦叶变绿过程中光合色素的 HPLC 测定。叶绿素生物合成的证据 a”FEBS Lett。（正在出版）。

小林正美, 他: "クロロフィルによる光合成反応中心の分類" 生物物理. 37(5). 196-200 (1997)

Masami Kobayashi 等人：“基于叶绿素的光合反应中心分类”，生物物理学 37(5) (1997)。