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: 10551343
• 负责人: KENNETH D. KARLIN
• 金额: $ 60.7万
• 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/10551343
• 关键词: Active Sites; Address; Basic Science; Binding; Biochemical; Biological; Carbon Dioxide; Chemistry; Complex; Copper; Copper Chelation; Coupled; Coupling; Development; Disease; Dopamine-beta-monooxygenase; Enzyme Inhibitor Drugs; Enzymes; Family; Health; Heme; Hydrogen Bonding; Hydrogen Peroxide; Hydroxylation; Investigation; Ions; Ligands; Ligation; Lytic; Mediating; Metals; Methane hydroxylase; Mixed Function Oxygenases; Modeling; Mole the mammal; Molecular; Nature; Nitric Oxide; Nitrogen Oxides; Nuclear; Oxidases; Oxidoreductase; Oxygen; Particulate; Peroxonitrite; Pharmaceutical Preparations; Phenols; Polysaccharides; Process; Proteins; Protons; Research; Role; Spectrum Analysis; Structure; Therapeutic; Water; cofactor; cytochrome c oxidase; design; electron donor; hyponitrite; metalloenzyme; peptidylglycine alpha-amidating monooxygenase; physical property; programs; small molecule

Project Summary Proposed investigations derive from two on-going R01 GM research programs. The study 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 (LPMOs), particulate methane monooxygenases (pMMOs), the enzyme family which includes dopamine beta-monooxygenase (DBM) and peptidylglycine monooxygenase (PHM), and a coupled binuclear copper protein, NspF. Recent 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 (H2O2 co-substrate), 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 versus a Cu2 center process. Relevant to these issues, there are clear needs to synthesize and characterize the thus-far elusive copper(II)-oxyl (CuII-O·) species; it has the oxidizing ability needed for the difficult LPMO or pMMO substrates. We also plan to elucidate fundamentals critical to the O-O reductive cleavage process occurring in all monooxygenases (& oxidases). Also, we will generate and characterize the structures, physical properties and reactivity of new high-valent binuclear Cu(II)-O-Cu(III) or related complexes. Otherwise, proposed research will focus on the heme-copper active site present in cytochrome c oxidases, where O2-binds and is reductively cleaved to give two mole-equiv water. The study of synthetic models can help elucidate details and aid an understanding of structure, O2-binding, proton or H-bonding facilitated O-O cleavage, and the role of the active-site phenol (in the His-Tyr cofactor) as a proton-electron donor. 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 especially the ligand for copper ion, are systematically varied. A variety of approaches are planned, including 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 copper complexes, the focus will be on NO(g) reductive coupling, and investigation of mechanisms pertaining to the NO(g) binding to metal ion(s), formation of the N–N bond giving putative hyponitrite N2O22– intermediates, and proton and/or H-bonding contributions to N–O cleavage and formation of N2O. Heme/Fe (or Cu) mediated NO(g) reductive coupling is critical in NO-Reductases and chemistry 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 in relation to the relevant biological activity.

项目摘要 拟议的调查源自两个正在进行的R01 GM研究计划。研究目标 包括合成模型的设计，合成和研究，这些模型将有助于阐明 与铜和血红素相关的结构，M结合，光谱和反应性的基本方面 （M = Cu，Fe）分子氧（O2（g））和一氧化氮（NO（G））的加工。关注的铜蛋白 包括裂解多糖单加氧酶（LPMOS），颗粒甲烷单加氧酶 （PMMOS），包括多巴胺β-单氧酶（DBM）和肽基甘氨酸的酶家族 单加氧酶（PHM）和偶联的纤维铜蛋白NSPF。最近的生化研究 已经提出了有关其主动地点的性质和涉及的行动机制的问题 O2（G）活化和C-H羟基化。 LPMO可能是过氧化物酶（H2O2共覆盖），新PMMO 研究表明一个单核活性位点，现在质疑DBM和PHM是否激活 O2具有CU与Cu2中心过程。与这些问题相关，有明确的需要综合 并表征如此罕见的难以捉摸的铜（II）-oxyl（CuII-O·）物种；它具有所需的氧化能力 对于困难的LPMO或PMMO底物。我们还计划阐明对O-O至关重要的基础知识 所有单氧酶（＆氧化物）中发生的还原性切割过程。另外，我们将生成并 表征新的高价值Binclear Cu（ii）-O-CU（III）的结构，物理特性和反应性 或相关的复合物。否则，拟议的研究将重点放在存在的血红素活跃部位上 在细胞色素c氧化物中，在其中o2结构并裂解以得到两种摩尔含量水。 合成模型的研究可以帮助阐明细节并帮助理解结构，O2结合， 质子或h键构制备的O-O裂解和活性位点酚的作用（在His-Tyr中 辅因子）作为质子电子供体。提出了调查以进一步研究机制 血红素 - 过氧 - 铜构建体中的O-O裂解 尤其是铜离子的配体有系统的变化。计划了各种方法， 包括研究新樱桃的铜，该铜拥有三个N donors和一个附加的苯酚。木栓） 还将执行与铜和血红素M的合成模型化学子项目。用铜 复合物，重点将放在耦合的（g）减少的耦合上，并研究了与 NO（G）与金属离子（S）的结合，N – N键的形成给出了推定的不足N2O22– 中间体以及质子和/或H键对N2O的裂解和形成的贡献。 血红素/Fe（或Cu）介导的NO（G）减少的耦合在无还原酶和化学中至关重要 将研究此过程的合成模型。金属 - 过氧亚硝酸盐（PN，来自金属离子 + O2（g） + NO（G））反应性，尤其是对CO2的反应性，也将与相关的生物学活性有关。