Sun Li-Juan, Wang Huamin, Xu Jia-Kun, Gao Shu-Qin, Wen Ge-Bo, Lin Ying-Wu
Hengyang Medical School, University of South China, Hengyang 421001, China.
School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China.
Inorg Chem. 2023 Oct 9;62(40):16294-16298. doi: 10.1021/acs.inorgchem.3c02855. Epub 2023 Sep 29.
It is desired to design and construct more efficient enzymes with better performance to catalyze carbene N-H insertions for the synthesis of bioactive molecules. To this end, we exploited and designed a series of human neuroglobin (Ngb) mutants. As shown in this study, a double mutant, A15C/H64G Ngb, with an additional disulfide bond and a modified heme active site, exhibited yields up to >99% and total turnover numbers up to 33000 in catalyzing the carbene N-H insertions for aromatic amine derivatives, including those with a large size such as 1-aminopyrene. Moreover, for -phenylenediamine derivatives, they underwent two cycles of N-H insertions, followed by cyclization to form quinoxalinones, as confirmed by the X-ray crystal structures. This study suggests that Ngb can be designed into a functional carbene transferase for efficiently catalyzing carbene N-H insertion reactions with a range of substrates. It also represents the first example of the formation of quinoxalinones catalyzed by an engineered heme enzyme.
人们期望设计和构建性能更优的高效酶，以催化卡宾N-H插入反应来合成生物活性分子。为此，我们开发并设计了一系列人神经球蛋白（Ngb）突变体。如本研究所示，一种具有额外二硫键和修饰血红素活性位点的双突变体A15C/H64G Ngb，在催化芳香胺衍生物（包括如1-氨基芘等大尺寸衍生物）的卡宾N-H插入反应中，产率高达>99%，总周转数高达33000。此外，对于对苯二胺衍生物，经X射线晶体结构证实，它们经历了两个N-H插入循环，随后环化形成喹喔啉酮。这项研究表明，Ngb可被设计成一种功能性卡宾转移酶，用于高效催化一系列底物的卡宾N-H插入反应。它也是工程化血红素酶催化形成喹喔啉酮的首个实例。
