Nitric oxide reactions in metalloenzymes

金属酶中的一氧化氮反应

基本信息

批准号：
8474781
负责人：
PIERRE MOENNE-LOCCOZ
金额：
$ 27.67万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8474781
关键词：
Active Sites Archaea Bacteria Binding Biochemical Reaction Biomedical Engineering Catalysis Characteristics Chemistry Complex Copper Coupling Drug Metabolic Detoxication Electron Spin Resonance Spectroscopy Electron Transport Engineering Environment Enzymes Event Exhibits Family Flavin Mononucleotide Freezing Goals Heme Hemerythrin Human Hydrogen Peroxide Immune response Iron Kinetics Lead Modeling Monitor Myoglobin Nitric Oxide Noble Gases Orthologous Gene Oxidases Oxidoreductase Pharmaceutical Preparations Play Proteins Protons Raman Spectrum Analysis Reaction Research Resistance Role Route Site Spectroscopy, Fourier Transform Infrared Structure System Variant X-Ray Crystallography bacterial resistance carboxylate cofactor cold temperature combat enzyme model heme a hyponitrite insight iron nitrosyl metalloenzyme microbial microorganism nitroxyl pathogen photolysis protonation public health relevance research study

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of this research is to elucidate the reaction mechanisms of NO reduction that occur at heme and non-heme diiron centers of bacterial metalloenzymes. Our studies will focus on two enzymatic systems and related bioengineered or synthetic models: 1) NO-detoxifying flavodiiron proteins (FDPs) and 2) denitrifying NO reductases (denNORs). All of the proteins within these two families are known to reduce NO to the unreactive N2O product, but they do so with wide variation in efficiency and protein matrix structure. Although several of these proteins have been characterized by X-ray crystallography, the initial steps of NO binding, iron-nitrosyl reduction, and how these catalytic events differ between systems are not well understood. The coupling of resonance Raman, FTIR, and EPR spectroscopies with rapid-freeze-quench analyses provides unique capabilities to define NO-binding geometries at diiron clusters and to follow the N-N bond formation, N-O bond cleavage, and protonation steps that must take place to convert two NO molecules to N2O and H2O. Studying a diverse group of native enzymes and models will allow us to compare and contrast structural information on iron-nitrosyl intermediates and the efficiency of the reductive and proton transfer steps of this reaction.

描述（由申请人提供）：这项研究的长期目标是阐明在细菌金属酶的血红素和非血红素二铁中心没有减少的反应机制。我们的研究将重点放在两个酶促系统和相关的生物工程或合成模型上：1）无氧化黄氧化铁蛋白（FDPS）和2）无还原酶（DENNORS）。已知这两个家族中的所有蛋白质都降低了不反应性N2O产品，但它们的效率和蛋白质基质结构的变化很大。尽管这些蛋白质中的几种以X射线晶体学为特征，但没有结合，亚硝基还原铁的初始步骤以及这些系统之间这些催化事件的差异尚未得到充分了解。共鸣拉曼，FTIR和EPR光谱与快速冻结分析的耦合提供了独特的功能，可以在二龙群集上定义无结合的几何形状，并遵循N-N键形成，N-O键的切割，以及必须将两种分子转换为N2O和N2O和H2O的蛋白质键的切割和蛋白质步骤。研究一组不同的天然酶和模型将使我们能够比较和对比有关硝基中间体的结构信息，以及该反应的还原性和质子传递步骤的效率。