Organization of the oxygen-evolution enzyme complex studied by butanol/water phase partitioning of spinach photosystem II particles.
Organization of the oxygen-evolution enzyme complex studied by butanol/water phase partitioning of spinach photosystem II particles.
复制标题
通过菠菜光系统 II 颗粒的丁醇/水相分配研究氧释放酶复合物的组织。
DOI：
10.1016/s0021-9258(19)57420-8
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Y. Yamamoto
中科院分区：
文献类型：
--
作者：
Y. Yamamoto
由菠菜叶绿体经短暂超声处理和 Triton X-100 处理制备的释氧光系统 II 颗粒进行丁醇/水相分配。相对分子质量为33,000、24,000和18,000道尔顿的光系统II的三种外围蛋白以及与光系统II相关的一部分锰原子被分配到水相中，这取决于光系统II颗粒悬浮液中包含的盐的浓度。在 pH 6.5 的各种离子条件下对光系统 II 颗粒的相分配进行定量分析表明：(a) 与光系统 II 相关的四个锰原子中的两个位于相对亲水的环境中，很容易从膜中提取； (b) 这些“亲水性锰原子”之一在结构上与相对分子质量为33,000道尔顿的蛋白质非常接近，并且被该蛋白质特异性地稳定； (c)相对分子质量为24,000道尔顿和33,000道尔顿的蛋白质参与膜中其他“亲水性锰”的稳定； (d) 三种蛋白质中的每一种在膜上都有一个独立的结合位点，并组织一个特定的催化结构域，在该结构域中与光系统 II 的反应中心合作有效地进行水的氧化。
The oxygen-evolving photosystem II particles prepared from spinach chloroplasts with brief sonication and Triton X-100 treatment were subjected to butanol/water phase partitioning. Three peripheral proteins of photosystem II having relative molecular masses of 33,000, 24,000, and 18,000 daltons and a part of the manganese atoms associated with photosystem II were partitioned into the aqueous phase, depending on the concentration of salt which was included in the suspension of the photosystem II particles. Quantitative analysis of the phase partitioning of the photosystem II particles under the various ionic conditions at pH 6.5 suggested the following: (a) two of the four atoms of manganese associated with photosystem II are located at a relatively hydrophilic environment and easily extracted from the membrane; (b) one of these “hydrophilic manganese atoms” is structurally in close proximity to the protein of the relative molecular mass of 33,000 daltons and stabilized by the protein specifically; (c) the protein of the relative molecular mass of 24,000 daltons as well as that of 33,000 daltons is involved in the stabilization of the other “hydrophilic manganese” in the membrane; (d) each of the three proteins has an independent binding site on the membrane and organizes a specific catalytic domain where oxidation of water is carried out efficiently in collaboration with the reaction center of photosystem II.