Nitrogen heterocycles are key and prevalent motifs in drugs. Evolved variants of cytochrome P450BM3 (CYP102A1) from Bacillus megaterium employ high-valent oxo-iron(iv) species to catalyze the synthesis of imidazolidine-4-ones via an intramolecular C-H amination. Herein, we use multi-scale simulations, including classical molecular dynamics (MD) simulations, quantum mechanical/molecular mechanical (QM/MM) calculations and QM calculations, to reveal the molecular mechanism of the intramolecular C-H amination of the pyrrolidine derivative of lidocaine bearing cyclic amino moieties catalyzed by the variant RP/FV/EV of P450BM3, which bears five mutations compared to wild type. Our calculations show that overall catalysis includes both the enzymatic transformation in P450 and non-enzymatic transformation in water solution. The enzymatic transformation involves the exclusive hydroxylation of the C-H bond of the pyrrolidine derivative of lidocaine, leading to the hydroxylated intermediate, during which the substrate radical would be bypassed. The following dehydration and C-N coupling reactions are found to be much favored in aqueous situation compared to that in the non-polar protein environment. The present findings expand our understanding of the P450-catalyzed C(sp3)-H amination reaction.

中文翻译：

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P450催化利多卡因吡咯烷衍生物胺化的分子机制：来自多尺度模拟的见解。

氮杂环是药物中的关键和普遍的基序。来自巨大芽孢杆菌的细胞色素 P450BM3 (CYP102A1) 的进化变体采用高价氧代铁 (iv) 物种通过分子内 CH 胺化催化 4-4 咪唑烷酮的合成。在此，我们使用多尺度模拟，包括经典分子动力学（MD）模拟、量子力学/分子力学（QM/MM）计算和QM计算，揭示利多卡因轴承吡咯烷衍生物分子内CH胺化的分子机制由 P450BM3 的变体 RP/FV/EV 催化的环状氨基部分，与野生型相比具有五个突变。我们的计算表明，整体催化包括 P450 中的酶促转化和水溶液中的非酶促转化。酶促转化涉及利多卡因的吡咯烷衍生物的 CH 键的独家羟基化，产生羟基化的中间体，在此期间底物自由基将被绕过。与非极性蛋白质环境相比，发现以下脱水和 CN 偶联反应在水环境中更受青睐。本研究结果扩展了我们对 P450 催化的 C(sp3)-H 胺化反应的理解。