Synthesis of Diiron Complexes of Relevence to Methane Monoxygenase

与甲烷单加氧酶相关的二铁配合物的合成

• 批准号: 7676554
• 负责人: Matthew A Cranswick
• 金额: $ 4.52万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-15 至 2012-04-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7676554
• 关键词: Active Sites; Aerobic; Amines; Anabolism; Bacteria; Biological; Carbon; Chemicals; Complex; Data; Electron Transport; Electronics; Enzymes; Hydrocarbons; Hydrogen Bonding; Iron; Kinetics; Lead; Ligands; Methane; Methane hydroxylase; Methanol; Methods; Mixed Function Oxygenases; Modeling; Natural Gas; Organism; Oxygen; Process; Property; Reaction; Research Project Grants; Ribonucleotide Reductase; Roentgen Rays; Route; Site; Source; Spectrum Analysis; Structure; Techniques; absorption; base; catalyst; data modeling; design; electronic structure; greenhouse gases; improved; insight; interest; novel; public health relevance; small molecule; social implication; success

DESCRIPTION (provided by applicant): Oxygen-activating diiron-enzymes are found in all aerobic organisms and utilize a diiron site to perform demanding chemical transformations. The major aim of this research project is to gain insight into the mechanism of oxygen-activation at diiron-enzyme active sites through the synthesis and characterization of high-valent, high-spin diiron-oxo complexes that mimic the structure and reactivity of key reaction intermediates. Specifically, novel diiron complexes will be utilized to model the reactive species of soluble methane monooxygenase (sMMO), an enzyme that utilizes methane as its sole source of carbon. The sequestration of methane by methanotropic bacteria is responsible for the elimination of nearly a billion tons of this potent greenhouse gas per year. In addition, there is considerable industrial interest in replicating the sMMO reaction to provide an environmentally-friendly process to generating methanol as a means of safely transporting natural gas reserves and as a chemical feedstock. The enzyme ribonucleotide reductase (RNR) also contains a similar diiron site that initiates long-range electron-transfer to the enzyme active site and is essential in DMA biosynthesis. Thus, understanding how the diiron site of sMMO and RNR activates oxygen to carry out their respective functions will have broad environmental and social implications. The crucial reactive intermediate in oxidizing methane to methanol is performed at a poorly understood diiron(IV)-oxo species known as intermediate Q, which is produced via the diiron(lll)-peroxo intermediate, P. Building upon the recent successes of generating high-valent diiron-complexes, this proposal describes the synthetic route to designing novel ligand motifs and small-molecule diiron model complexes that reproduce the geometric and electronic structures of P and Q. These diiron-complexes will be characterized by a variety of spectroscopic and structural methods, including electronic absorption, resonance Raman, Mossbauer and X-ray absorption spectroscopies, and their reactivity towards organic substrates will be evaluated. PUBLIC HEALTH RELEVANCE: This proposal outlines the synthesis of small-molecule diiron-complexes that replicate the structure and reactivities of important biological species and aims to further our understanding of how processes that require oxygen-activation are carried out at diiron centers by these enzymes. Additionally, this project may lead to better catalysts that will allow chemists to utilize oxygen to carry out environmentally friendly transformations of hydrocarbons, thereby reducing greenhouse emissions.

描述（由申请人提供）：在所有有氧生物中都发现了氧气激活二氮 - 酶，并利用二铁部位进行苛刻的化学转化。该研究项目的主要目的是通过合成和表征高价值的高旋转二氧氧化型复合物的合成和表征来了解二氮 - 酶活性位点上的氧气激活机制，从而模仿了关键反应中间体的结构和反应性。具体而言，新型的二烷复合物将用于建模可溶性甲烷单加尝试酶（SMMO）的反应性物种，该酶利用甲烷作为其唯一的碳来源。通过甲烷细菌将甲烷隔离是为了消除每年近十亿吨这种有效的温室气体。此外，复制SMMO反应以提供环保的过程来产生甲醇作为安全运输天然气储量和化学原料的一种手段，具有很大的工业兴趣。酶核糖核苷酸还原酶（RNR）还包含一个类似的二烯位点，该位点启动了远程电子转移到酶的活性位点，并且在DMA生物合成中至关重要。因此，了解SMMO和RNR的二铁站点如何激活氧气以执行各自的功能将具有广泛的环境和社会影响。在不理会的二铁（IV） - 氧化物种中进行的氧化甲烷中的至关重要的反应性中间体被称为中间Q，这是通过二龙（LLL） - 过敏中间体生产的，P。建立在最新产生的高价值二氧化型的成功率的成功基础上。重现P和Q的几何和电子结构的二龙模型复合物。这些二铁复合物的特征将以各种光谱和结构方法的特征，包括电子吸收，共振拉曼，Mossbauer和X射线吸收光谱镜以及它们对有机物的反应性。公共卫生相关性：该提案概述了复制重要生物物种的结构和重复性的小分子二氮化物的综合，并旨在进一步理解我们如何通过这些酶在二铁中心进行需要氧气激活的过程。此外，该项目可能会导致更好的催化剂，从而使化学家能够利用氧气对碳氢化合物进行环保转换，从而减少温室的排放。