Necessity of structural rearrangements for O O bond formation between O5 and W2 in photosystem II
| Autor: | Biaobiao Zhang, Lars Kloo, Yu Guo, Licheng Sun |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Photosystem II
Chemistry Stereochemistry Energy Engineering and Power Technology Substrate (chemistry) 02 engineering and technology Bond formation 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Fuel Technology Catalytic cycle Electrochemistry Cluster (physics) 0210 nano-technology Energy (miscellaneous) |
| Zdroj: | Journal of Energy Chemistry. 57:436-442 |
| ISSN: | 2095-4956 |
| Popis: | Numerous aspects of the water oxidation mechanism in photosystem II have not been fully elucidated, especially the O O bond formation pathway. However, a body of experimental evidences have identified the O5 and W2 ligands of the oxygen-evolving complex as the highly probable substrate candidates. In this work, we studied O O bond formation between O5 and W2 based on the native Mn4Ca cluster by density functional calculations. Structural rearrangements before the formation of the S4 state were found as a prerequisite for O O bond formation between O5 and W2, regardless if the suggested pathways involving the typical Mn1(IV)-O species or the recently proposed Mn4(VII)(O)2 species. Possible alternatives for the S2 → S3 and S3 → S4 transitions accounting for such required rearrangements are discussed. These findings reflect that the structural flexibility of the Mn4Ca cluster is essential to allow structural rearrangements during the catalytic cycle. |
| Databáze: | OpenAIRE |
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