Reactivity-Activation of O(2) or NO in Copper and Heme-Cu Coordination Complexes

铜和血红素-Cu 配位络合物中 O(2) 或 NO 的反应活性活化

• 批准号: 10389306
• 负责人: KENNETH D. KARLIN
• 金额: $ 12.48万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10389306
• 关键词: Active Sites; Address; Basic Science; Binding; Biochemical; Biochemistry; Biological; Carbon Dioxide; Cell physiology; Chelating Agents; Chemistry; Cleaved cell; Complex; Copper; Coupling; Development; Disease; Enzyme Inhibitor Drugs; Enzymes; Equipment; Family; Funding; Gases; Health; Heme; Heme Iron; Hydrogen Bonding; Hydroxylation; Investigation; Ions; Ligands; Ligation; Lytic; Mediating; Metals; Methane hydroxylase; Mixed Function Oxygenases; Modeling; Mole the mammal; Molecular; Nature; Nitric Oxide; Nitrogen Oxides; Oxides; Oxidoreductase; Oxygen; Peroxonitrite; Pharmaceutical Preparations; Phenols; Polysaccharides; Process; Proteins; Protons; Research; Role; Spectrum Analysis; Structure; Therapeutic; Water; cytochrome c oxidase; design; experimental study; hyponitrite; instrument; ionization; mass spectrometer; peptidylglycine alpha-amidating monooxygenase; physical property; small molecule

Project Summary/Abstract: This equipment supplement project proposal seeks funds to purchase a Cold-Spray Ionization Mass Spectrometer to carry out CSI-MS experiments, a powerful approach to characterizing typically unstable reactive intermediates. The scientific objectives include the design, synthesis & investigation of synthetic models which will aid the elucidation of fundamental aspects of structure, M-ligation, spectroscopy and reactivity relevant to copper and heme/M (M = Cu, Fe) processing of molecular oxygen (O2(g)) and nitric oxide (NO(g)). Copper proteins of concern include lytic polysaccharide monooxygenases, Cu-methane monooxygenases, the enzyme family which includes peptidylglycine monooxygenase, and a binuclear copper protein, NspF. Biochemical research has raised questions concerning the nature of their active sites and the mechanism(s) of action involving O2(g) activation and C-H hydroxylation. LPMOs may be peroxygenases, new pMMO studies suggest a mono-Cu active site, and it is now questioned as to whether DBM and PHM activate O2 with a Cu vs a Cu2 center. There are clear needs to synthesize and characterize the copper(II)-oxyl (CuII-O·) species; it has the oxidizing ability needed for the difficult biological substrates. We also plan to elucidate fundamentals critical to the O-O reductive cleavage process occurring in proteins which process O2. Also, we will generate and characterize the structures, physical properties and reactivity of new high-valent binuclear Cu(II)-O-Cu(III) complexes. Proposed research will also focus on the heme-copper active site of cytochrome c oxidases, where O2-binds and is reductively cleaved to give two mole-equiv water. The study of synthetic models aids an understanding of structure, O2-binding, proton or H-bonding facilitated O-O cleavage, and the role of the active-site phenol. Investigations are proposed to further investigate the mechanisms of O-O cleavage in heme-peroxo-copper constructs, where the porphyrinate, the Fe axial ligand and the copper ligand are systematically varied. A variety of planned approaches include study of new chelates for copper which possess three N-donors and an appended phenol. NO(g) synthetic model chemistry sub-projects with copper and heme-M will also be carried out. With Cu complexes, the focus will be on NO(g) reductive coupling, and study of mechanisms pertaining to the NO(g) metal-binding, formation of the N–N bond giving putative hyponitrite N2O22– intermediates, and proton and/or H-bonding contributions to N–O cleavage and N2O formation. Heme/Fe (or Cu) mediated NO(g) coupling is critical in NO-Reductases and synthetic models for this process will be investigated. Metal-peroxynitrite (PN, from metal ion + O2(g) + NO(g)) reactivity, especially toward CO2, will also be studied as relevant to biological activity.

项目摘要/摘要： 该设备补充项目提案寻求资金购买冷喷雾电离 进行CSI-MS实验的质谱仪，一种表征的强大方法 通常是不稳定的反应性中间体。科学对象包括设计，合成和 调查合成模型，这些模型将有助于阐明结构的基本方面， 与铜和血红素/M（M = Cu，Fe）加工有关的M结合，光谱和反应性 分子氧（O2（G））和一氧化氮（NO（G））的含量。关注的铜蛋白包括裂解 多糖单加氧酶，Cu-甲烷单加氧酶，酶家族，该酶家族 包括肽基甘氨酸单加氧酶和均质铜蛋白NSPF。生化 研究提出了有关其主动地点的性质和机制的问题 涉及O2（G）激活和C-H羟基化的作用。 lpmos可能是过氧化物酶，新的 PMMO研究建议一个单一的活动部位，现在质疑DBM和是否是否 PHM用Cu与Cu2中心激活O2。明确需要合成和表征 铜（II）-Oxyl（CuII-O·）物种；它具有困难的生物学所需的氧化能力 基材。我们还计划阐明对O-O减少裂解过程至关重要的基础知识 发生在O2过程的蛋白质中。另外，我们将生成和表征结构， 新高价值双核Cu（II）-O-Cu（III）配合物的物理特性和反应性。 拟议的研究还将集中于细胞色素C氧化酶的血红素活性部位，即 o2结合并减少裂解以得到两个摩尔含量水。合成研究 模型有助于了解制备的O-O的结构，O2结合，质子或H键键 裂解和活性位点酚的作用。提出了调查以进一步调查 O-O裂解在血红素 - 过氧 - 波普构建体中的机理，卟啉酸酯， Fe轴向配体和铜配体有系统的变化。各种计划的方法 包括研究新樱桃的铜的研究，该铜拥有三个N donors和一个附加的苯酚。 也将进行无铜和血红素M的NO（G）合成模型化学对象。 使用CU复合物，重点将放在NO（G）减少的耦合上，并研究机制 与NO（G）金属结合有关 中间体以及质子和/或H键对N – O裂解和N2O形成的贡献。 血红素/Fe（或Cu）介导的NO（G）耦合在NO-REDUCTass和合成模型中至关重要 该过程将进行调查。金属 - 过氧亚硝酸盐（PN，来自金属离子 + O2（g） + NO（G））反应性， 尤其是针对二氧化碳，还将研究与生物活性有关。