Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan.
Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan.
Angew Chem Int Ed Engl. 2019 Sep 23;58(39):13813-13817. doi: 10.1002/anie.201907584. Epub 2019 Aug 23.
Myoglobin reconstituted with Ni tetradehydrocorrin was investigated as a model of F430-containing methyl-coenzyme M reductase, which catalyzes anaerobic methane generation. The Ni tetradehydrocorrin complex has a Ni /Ni redox potential of -0.34 V vs. SHE and EPR spectroscopy indicates the formation of a Ni species upon reduction by dithionite. This redox potential is approximately 0.31 V more positive than that of F430. The Ni tetradehydrocorrin moiety is bound to the apo-form of myoglobin to yield the reconstituted protein. Methane gas is generated in the reaction of the model with methyl iodide in the presence of the reconstituted protein under reductive conditions, whereas the Ni complex itself does not produce methane gas. This is the first example of a protein-based functional model of F430-containing methyl-coenzyme M reductase.
用 Ni 十四氢原卟啉重组的肌红蛋白被用作含有 F430 的甲基辅酶 M 还原酶的模型进行研究，该酶催化厌氧甲烷生成。Ni 十四氢原卟啉络合物具有相对于 SHE 的 Ni/Ni 氧化还原电位为-0.34 V，并且电子顺磁共振光谱表明，在二硫代苏糖醇还原时形成 Ni 物种。该氧化还原电位比 F430 的正约 0.31 V。Ni 十四氢原卟啉部分与脱辅基肌红蛋白结合，生成重组蛋白。在还原条件下，在存在重组蛋白的情况下，该模型与碘化甲基反应生成甲烷气体，而 Ni 络合物本身不产生甲烷气体。这是第一个基于蛋白质的含 F430 的甲基辅酶 M 还原酶功能模型的实例。
