Interactions of N-hydroxyamphetamine with an iron porphyrin: A unique intramolecular H-bond probed by DFT calculations
Interactions of N-hydroxyamphetamine with an iron porphyrin: A unique intramolecular H-bond probed by DFT calculations
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DOI：
10.1016/j.jinorgbio.2022.111779
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发表时间：
2022-03-11
影响因子：
3.9
通讯作者：
Richter-Addo，George B.
中科院分区：
文献类型：
--
作者：
Guan，Ye;Londono-Salazar，Jennifer;Richter-Addo，George B.
羟胺（NH2OH）及其取代衍生物（RNHOH）是全球氮循环中重要的生物中间体。血红素在这些羟胺的结合和激活中起着核心作用。我们报道了n -羟安非他明（AmphNHOH）与铁和钴血红素配合物模型的晶体结构。我们证明了在羟胺rnho - h基团和卟啉n原子之间以前未被识别的内部氢键相互作用。我们利用密度泛函理论（DFT）计算表明，具有内部氢键的构象沿Fe和Co血红素模型的势能面呈现全局最小值。自然键轨道（NBO）分析表明，铁的供体π (porN=C)与受体σ* (O-H)相互作用为3.04 kcal/mol，占血红素- amphnhoh总相互作用能的11%。我们对母体Fe-NH2OH的DFT计算表明，羟胺（R/H） nhoh基团和血红素n原子之间的内部氢键的存在可能比以前认识到的更普遍。
Hydroxylamine (NH2OH) and itsN-substituted derivatives (RNHOH) are important biological intermediates in the global N cycle. Heme plays a central role in the binding and activation of these hydroxylamines. We report the crystal structures ofN-hydroxyamphetamine (AmphNHOH) in complex with Fe and Co heme models. We demonstrate a previously unrecognized internal H-bond interaction between a hydroxylamine RNHO–Hgroup and a porphyrin N-atom. We utilize density functional theoretical (DFT) calculations to show that the conformations with the internal H-bond represent global minima along the potential energy surfaces for both the Fe and Co heme models. A natural bond orbital (NBO) analysis reveals a donor π (porN=C) to acceptor σ* (O-H) interaction of 3.04 kcal/mol for Fe, accounting for 11% of the total heme–AmphNHOH interaction energy. Our DFT calculations with the parent Fe–NH2OH suggests that the presence of internal H-bonds between hydroxylamine (R/H)NHOHmoieties and heme N-atoms may be more common than previously recognized.