Research School of Chemistry, The Australian National University, Canberra ACT 2601, Australia; email:
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr, Germany; email:
Annu Rev Biochem. 2020 Jun 20;89:795-820. doi: 10.1146/annurev-biochem-011520-104801. Epub 2020 Mar 24.
The investigation of water oxidation in photosynthesis has remained a central topic in biochemical research for the last few decades due to the importance of this catalytic process for technological applications. Significant progress has been made following the 2011 report of a high-resolution X-ray crystallographic structure resolving the site of catalysis, a protein-bound MnCaO complex, which passes through ≥5 intermediate states in the water-splitting cycle. Spectroscopic techniques complemented by quantum chemical calculations aided in understanding the electronic structure of the cofactor in all (detectable) states of the enzymatic process. Together with isotope labeling, these techniques also revealed the binding of the two substrate water molecules to the cluster. These results are described in the context of recent progress using X-ray crystallography with free-electron lasers on these intermediates. The data are instrumental for developing a model for the biological water oxidation cycle.
在过去几十年中，由于该催化过程对技术应用的重要性，光合作用中水氧化的研究一直是生物化学研究的核心课题。自 2011 年报道高分辨率 X 射线晶体学结构解析催化位点（一种结合 MnCaO 的蛋白质复合物）以来，该研究取得了重大进展，该复合物在水分解循环中经历了≥5 个中间状态。光谱技术与量子化学计算相辅相成，有助于理解酶促过程中所有（可检测）状态下辅助因子的电子结构。结合同位素标记，这些技术还揭示了两个底物水分子与该簇的结合。本文在使用自由电子激光对这些中间产物进行 X 射线晶体学研究的最新进展背景下进行了描述。这些数据对于开发生物水氧化循环的模型非常重要。
