Water oxidation occurring in oxygenic natural photosynthesis is catalyzed by the protein-cofactor complex Photosystem II. The catalytic cycle leading to the water splitting into protons, electrons and molecular oxygen, consists of five consecutive steps, namely S₀-S₄. Here, using QM/MM Molecular Dynamics simulations, we characterized structural and magnetic properties of the putative S₄ state prior to O₂ release, considering two different spin multiplicities. Our results show an overall stability for both simulated systems in the ps timescale. Nonetheless, analysis of structural and magnetic properties identified discrepancies between the two simulations, conceivably having different consequences on the O₂ evolution.

含氧自然光合作用中发生的水氧化被蛋白质辅因子复合物光系统II催化。导致水分裂成质子，电子和分子氧的催化循环包括五个连续步骤，即S ₀ -S ₄。在这里，使用QM / MM分子动力学模拟，我们考虑了两个不同的自旋多重性，表征了O ₂释放之前假定的S ₄状态的结构和磁性。我们的结果显示了两个仿真系统在ps时间范围内的总体稳定性。尽管如此，对结构和磁性能的分析发现了两个模拟之间的差异，可以想见，它们对O的影响不同。₂进化。