控制光系统II中氧化还原潜力的控制:电子转移和光保护
Hiroshi Ishikita1, Ernst-Walter Knapp
1Institute of Chemistry and Biochemistry, Crystallography, Free University of Berlin, Takustrasse 6, D-14195 Berlin, Germany.
Journal of the American Chemical Society
|October 20, 2005
概括
光系统II (PSII) 中的电子转移依赖于的氧化还原潜力. 与塑基 (Q ((A)) 和Q ((B)) 位点的键显著影响这些潜能,影响光合作用效率和光保护.
科学领域:
- 生物化学 生物化学
- 光合作用研究研究光合作用.
- 结构生物学是结构生物学.
背景情况:
- 进化氧的复杂光系统II (PSII) 中高效的光合作用需要不受阻碍的电子从塑基 (Q(A)) 转移到Q(B).
- 最近的晶体结构为围绕Q (A) /Q (B) 结合点的蛋白质环境提供了洞察力.
研究的目的:
- 计算一个电子还原的塑基 (Q(A) /Q(B)) 氧化还原潜力 (E(m)) ,并纳入完整的PSII蛋白环境.
- 研究结模式在调节这些氧化还原潜力的作用及其功能影响.
主要方法:
- 塑基 (Q(A) /Q(B)) 氧化还原潜力的计算计算 (E(m)).
- 在光系统II中的Q (A) 和Q (B) 结合位点内分析键模式.
主要成果:
- 确定了两种不同的键模式,涉及Q(A) 和D2-Thr217,其中一种模式将E(m) ((Q(A)) 上调100mV.
- 对Q (A) 存在键可能有助于光保护机制.
- 与Q(B) 的结取决于D1-His252的质子化状态,其存在导致Q(B) 的高电位形式.
结论:
- 结合模式显著影响PSII中的塑基氧化还原潜力.
- 已识别的键模式保留在细菌光合作用反应中心 (bRC),这表明它在电子转移功能中起着基本作用.
- 这些发现为PSII的光合作用效率和光保护提供了机制性的见解.
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