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 用于进行 CSI-MS 实验的质谱仪，这是一种强大的表征方法 典型的不稳定反应中间体的科学目标包括设计、合成和 合成模型的研究将有助于阐明结构的基本方面， 与铜和血红素/M（M = Cu、Fe）加工相关的 M 连接、光谱学和反应性 分子氧 (O2(g)) 和一氧化氮 (NO(g)) 的影响包括裂解铜蛋白。 多糖单加氧酶、铜甲烷单加氧酶、 包括肽基甘氨酸单加氧酶和双核铜蛋白 NspF Biochemical。 研究提出了有关其活性位点的性质和机制的问题 涉及 O2(g) 活化和 C-H 羟基化的作用可能是新的过氧化酶。 pMMO 研究表明存在单铜活性位点，现在人们质疑 DBM 和 PHM 用 Cu 与 Cu2 中心激活 O2 显然需要合成和表征。 铜(II)-氧基(CuII-O·)物种具有困难的生物所需的氧化能力； 我们还计划阐明 O-O 还原裂解过程的关键基本原理。 发生在处理 O2 的蛋白质中，我们还将生成并表征结构， 新型高价双核 Cu(II)-O-Cu(III) 配合物的物理性质和反应性。 拟议的研究还将重点关注细胞色素 C 氧化酶的血红素铜活性位点， 其中 O2-结合并还原裂解得到两摩尔当量的水 合成的研究。 模型有助于理解结构、O2 结合、质子或氢键促进的 O-O 建议进一步研究裂解和活性位点苯酚的作用。 血红素-过氧化铜结构中 O-O 裂解的机制，其中卟啉、 Fe轴向配体和铜配体有系统地变化多种计划方法。 包括对具有三个氮供体和附加苯酚的新铜螯合物的研究。 铜和血红素-M 的 NO(g) 合成模型化学子项目也将开展。 对于 Cu 配合物，重点将放在 NO(g) 还原偶联和机理研究上 与 NO(g) 金属结合有关，形成 N-N 键，给出推定的次亚硝酸盐 N2O22– 中间体，以及质子和/或氢键对 N-O 裂解和 N2O 形成的贡献。 血红素/Fe（或 Cu）介导的 NO(g) 偶联在 NO 还原酶和合成模型中至关重要 将研究金属过氧亚硝酸盐（PN，来自金属离子 + O2(g) + NO(g)）的反应性， 特别是对于二氧化碳，也将研究其与生物活性的相关性。