ASSESSING THE CORE STRUCTURE OF A STABLE PEROXO DIIRON INTERMEDIATE IN THE AMINE

评估胺中稳定的过氧化二铁中间体的核心结构

• 批准号: 8170246
• 负责人: MICHAEL T. GREEN
• 金额: $ 0.27万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8170246
• 关键词: 4-Aminobenzoic Acid; Acids; Amines; Antibiotics; Biochemical; Biological; Charge; Computer Retrieval of Information on Scientific Projects Database; Electrons; Enzymes; Exhibits; Funding; Grant; Heme Iron; Institution; Iron; Isomerism; Kinetics; Methane hydroxylase; Optics; Oxygenases; Peroxides; Reaction; Research; Research Personnel; Resources; Source; Structure; Techniques; United States National Institutes of Health; aureothin; member; novel; oxidation

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. AurF, a novel oxygenase from S. thioluteus, catalyzes the unusual 6-electron oxidation of p- aminobenzoic acid (pABA) to p-nitrobenzoic acid (pNBA), an essential structural component of the antibiotic aureothin. We have demonstrated that AurF is a member of dinuclear non-heme- iron enzymes that are involved in numerous biological oxidation reactions (e.g. soluble methane monooxygenase). Using a combination of biochemical, kinetic, and spectroscopic techniques, we have identified a chemically competent peroxo-diiron(III/III) intermediate in this reaction. In the absence of substrate, pABA, this intermediate accumulates to nearly stoichiometric amounts, but it readily oxidizes the substrate. The peroxo-diiron(III/III) intermediate has markedly different spectroscopic parameters compared to other, well characterized peroxo-diiron(III/III) that are believed to have a ?-1,2-peroxo unit. Its optical transition (possibly a peroxide-to-iron charge transfer band) is observed around 500 nm, and it has a M¿ssbauer isomer shift of beta = 0.50 mm/s. ?-1,2-Peroxo-diiron(III/III) intermediates exhibit M¿ssbauer isomer shifts beta > 0.60 mm/s and a LMCT band at ~700 nm.

该副本是使用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这是调查员的机构。 Aurf是一种来自硫醇链球菌的新型氧化酶，催化了p-氨基苯甲酸（PABA）的异常6电子氧化物到p-硝基苯甲酸（PNBA），这是抗生素金黄色素的必不可少的结构成分。我们已经证明，Aurf是参与许多生物氧化物反应（例如可溶性甲烷单加氧酶）的双核非血红素酶的成员。使用生化，动力学和光谱技术的组合，我们确定了该反应中的化学合理的过氧二聚体（III/III）中间体。在没有底物的情况下，PABA，该中间体积累到几乎化学计量量，但很容易氧化底物。与其他据信具有？-1,2-过敏单元相比，过氧二氧化碳（III/III）中间体具有明显不同的光谱参数。在500 nm左右观察到它的光学跃迁（可能是过氧化物到铁的电荷转移带），并且具有β= 0.50 mm/s的M ssbauer异构体移位。 ？-1,2-Peroxo-Diiron（III/III）中间体表现出m ssbauer异构体beta beta> 0.60 mm/s和〜700 nm的LMCT带。