Lee Chi Chung, Hu Yilin, Ribbe Markus W
Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, 92697-3900, USA.
Department of Chemistry, University of California, Irvine, CA, 92697-2025, USA.
Chembiochem. 2025 Jun 16:e2500366. doi: 10.1002/cbic.202500366.
Nitrogenase is a versatile metalloenzyme that activates and reduces small molecules like N, CO, and CO into value-added chemicals at ambient conditions. Previously, it is shown that the Mo-nitrogenase could reduce CO to CO, but not to hydrocarbons, in an ATP-dependent reaction. Here, it is reported that the ability of the catalytic component of Mo-nitrogenase (MoFe protein) enables ATP-independent reduction of CO to up to C hydrocarbons in room-temperature reactions driven by a chemical reductant (Eu-DTPA) or visible light (via CdS@ZnS (CZS) quantum dots). Moreover, an opposite deuterium isotope effect is observed on the Eu-DTPA driven reactions of CO reduction by MoFe protein and its V-counterpart (VFe protein), in that the former displays higher activities in HO, and the latter displays higher activities in DO. These results provide an important foundation for further mechanistic exploration of the nitrogenase-enabled, atypical Fischer-Tropsch type reaction that uses CO instead of CO as a substrate; moreover, they serves as a potential template for the future development of nitrogenase-based applications that effectively recycle the greenhouse gas CO into valuable fuel products.
固氮酶是一种多功能金属酶，可在环境条件下将诸如N₂、CO和CO₂等小分子活化并还原为增值化学品。此前研究表明，钼固氮酶在依赖ATP的反应中可将CO还原为CO₂，但无法还原为碳氢化合物。在此报告中，发现钼固氮酶的催化组分（MoFe蛋白）能够在由化学还原剂（Eu-DTPA）或可见光（通过CdS@ZnS（CZS）量子点）驱动的室温反应中，实现不依赖ATP将CO还原为含碳数高达C的碳氢化合物。此外，在MoFe蛋白及其钒对应物（VFe蛋白）催化的Eu-DTPA驱动的CO还原反应中观察到相反的氘同位素效应，即前者在H₂O中活性更高，后者在D₂O中活性更高。这些结果为进一步探索以CO而非CO₂为底物的固氮酶介导的非典型费托型反应的机理提供了重要基础；此外，它们还为未来基于固氮酶的应用开发提供了潜在模板，这种应用可将温室气体CO有效地循环转化为有价值的燃料产品。
