Institut für Chemie, Technische Universität Berlin, Sekretariat PC 14, 10623, Berlin, Germany.
Institut für Biologie, Strukturbiologie/Biochemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.
Angew Chem Int Ed Engl. 2017 Jun 19;56(26):7398-7401. doi: 10.1002/anie.201703225. Epub 2017 May 23.
The biocatalytic function of carbon monoxide dehydrogenase (CODH) has a high environmental relevance owing to its ability to reduce CO . Despite numerous studies on CODH over the past decades, its catalytic mechanism is not yet fully understood. In the present combined spectroscopic and theoretical study, we report first evidences for a cyanate (NCO ) to cyanide (CN ) reduction at the C-cluster. The adduct remains bound to the catalytic center to form the so-called CN -inhibited state. Notably, this conversion does not occur in crystals of the Carboxydothermus hydrogenoformans CODH enzyme (CODHII ), as indicated by the lack of the corresponding CN stretching mode. The transformation of NCO , which also acts as an inhibitor of the two-electron-reduced C state of CODH, could thus mimic CO turnover and open new perspectives for elucidation of the detailed catalytic mechanism of CODH.
一氧化碳脱氢酶（CODH）的生物催化功能因其能够还原 CO 而具有很高的环境相关性。尽管在过去几十年中对 CODH 进行了大量研究，但它的催化机制仍未完全理解。在本项结合光谱和理论的研究中，我们首次报道了在 C 簇中发生的氰酸盐（NCO ）到氰化物（CN ）的还原证据。加合物仍然与催化中心结合，形成所谓的 CN 抑制态。值得注意的是，这种转化不会发生在 Carboxydothermus hydrogenoformans CODH 酶（CODHII ）的晶体中，这表明缺乏相应的 CN 伸缩模式。因此，NCO 的转化也可以模拟 CO 的转化，为阐明 CODH 的详细催化机制开辟新的前景，因为 NCO 也可以作为 CODH 两电子还原 C 态的抑制剂。
