Fataftah Majed S, Wilson Daniel W N, Mathe Zachary, Gerard Theodore J, Mercado Brandon Q, DeBeer Serena, Holland Patrick L
Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.
Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.
ACS Cent Sci. 2024 Oct 3;10(10):1910-1919. doi: 10.1021/acscentsci.4c00985. eCollection 2024 Oct 23.
Metalloenzymes can efficiently achieve the multielectron interconversion of carbon dioxide and carbon monoxide under mild conditions. Anaerobic carbon monoxide dehydrogenase (CODH) performs these reactions at the cluster, a unique nickel-iron-sulfide cluster that features an apparent three-coordinate nickel site. How nature assembles the [NiFeS]-Fe cluster is not well understood. We use synthetic clusters to demonstrate that electron transfer can drive insertion of a Ni precursor into an [FeS] cluster to assemble higher nuclearity nickel-iron-sulfide clusters with the same complement of metal ions as the cluster. Initial electron transfer results in a [1Ni-4Fe-4S] cluster in which a Ni ion sits outside of the cluster. Modifying the Ni precursor results in the insertion of two nickel atoms into the cluster, concomitant with ejection of an iron to yield an unprecedented [2Ni-3Fe-4S] cluster possessing four three-coordinate metal sites. Both clusters are characterized using magnetometry, electron paramagnetic resonance (EPR), Mössbauer, and X-ray absorption spectroscopy and supported by DFT computations that are consistent with both clusters having nickel in the +1 oxidation state. These results demonstrate that Ni is a viable oxidation state within iron-sulfur clusters and that redox-driven transformations can give rise to higher nuclearity clusters of relevance to the CODH cluster.
金属酶能够在温和条件下高效地实现二氧化碳和一氧化碳之间的多电子相互转化。厌氧一氧化碳脱氢酶（CODH）在该簇合物上进行这些反应，该簇合物是一种独特的镍 - 铁 - 硫簇合物，具有一个明显的三配位镍位点。目前尚不清楚自然界是如何组装[NiFeS]-Fe簇合物的。我们使用合成簇合物来证明电子转移可以驱动镍前体插入到[FeS]簇合物中，从而组装出与该簇合物具有相同金属离子组成的更高核数的镍 - 铁 - 硫簇合物。初始电子转移产生一个[1Ni - 4Fe - 4S]簇合物，其中一个镍离子位于簇合物外部。改变镍前体导致两个镍原子插入到簇合物中，同时有一个铁原子被排出，从而产生一个前所未有的[2Ni - 3Fe - 4S]簇合物，该簇合物具有四个三配位金属位点。使用磁测量、电子顺磁共振（EPR）、穆斯堡尔谱和X射线吸收光谱对这两种簇合物进行了表征，并得到了密度泛函理论（DFT）计算的支持，这些计算与两种簇合物中的镍均处于 +1 氧化态相一致。这些结果表明镍在铁硫簇合物中是一种可行的氧化态，并且氧化还原驱动的转变可以产生与CODH簇合物相关的更高核数的簇合物。
