Chloride facilitates Mn(III) formation during photoassembly of the Photosystem II oxygen-evolving complex

被引：0
作者：
Brandon P. Russell
David J. Vinyard
机构：
[1] Louisiana State University,Department of Biological Sciences
来源：
Photosynthesis Research | 2022年 / 152卷
关键词：
Photosystem II; Oxygen-evolving complex; Assembly; Electron paramagnetic resonance spectroscopy;
D O I：
暂无
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学科分类号：
摘要：
The Mn4Ca oxygen-evolving complex (OEC) in Photosystem II (PSII) is assembled in situ from free Mn2+, Ca2+, and water. In an early light-driven step, Mn2+ in a protein high-affinity site is oxidized to Mn3+. Using dual-mode electron paramagnetic resonance spectroscopy, we observed that Mn3+ accumulation increases as chloride concentration increases in spinach PSII membranes depleted of all extrinsic subunits. At physiologically relevant pH values, this effect requires the presence of calcium. When combined with pH studies, we conclude that the first Mn2+ oxidation event in OEC assembly requires a deprotonation that is facilitated by chloride.
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页码：283 / 288
页数：5
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