Cha Lide, Paris Jared C, Zanella Brady, Spletzer Martha, Yao Angela, Guo Yisong, Chang Wei-Chen
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States.
Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
J Am Chem Soc. 2023 Mar 22;145(11):6240-6246. doi: 10.1021/jacs.2c12664. Epub 2023 Mar 13.
Aziridines are compounds with a nitrogen-containing three-membered ring. When it is incorporated into natural products, the reactivity of the strained ring often drives the biological activities of aziridines. Despite its importance, the enzymes and biosynthetic strategies deployed to install this reactive moiety remain understudied. Herein, we report the use of methods to identify enzymes with potential aziridine-installing (aziridinase) functionality. To validate candidates, we reconstitute enzymatic activity and demonstrate that an iron(IV)-oxo species initiates aziridine ring closure by the C-H bond cleavage. Furthermore, we divert the reaction pathway from aziridination to hydroxylation using mechanistic probes. This observation, isotope tracing experiments using HO and O, and quantitative product analysis, provide evidence for the polar capture of a carbocation species by the amine in the pathway to aziridine installation.
氮杂环丙烷是一类含有含氮三元环的化合物。当它被整合到天然产物中时，这种张力环的反应活性常常驱动着氮杂环丙烷的生物活性。尽管其很重要，但用于安装这种反应性部分的酶和生物合成策略仍未得到充分研究。在此，我们报告了使用多种方法来鉴定具有潜在氮杂环丙烷安装（氮杂环丙烷化酶）功能的酶。为了验证候选酶，我们重构了酶活性，并证明一个铁（IV）-氧物种通过碳-氢键裂解引发氮杂环丙烷环的闭合。此外，我们使用机理探针将反应途径从氮杂环丙烷化转变为羟基化。这一观察结果、使用H₂O和¹⁸O的同位素示踪实验以及定量产物分析，为在氮杂环丙烷安装途径中胺对碳正离子物种的极性捕获提供了证据。
