MODELING COPPER PROTEIN--NITROGEN OXIDE INTERACTIONS

铜蛋白-一氧化氮相互作用建模

• 批准号: 2184765
• 负责人: WILLIAM B Tolman
• 金额: $ 11.89万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2184765
• 关键词: active sites; adduct; chemical synthesis; copper; enzyme model; enzyme substrate complex; metal complex; metalloenzyme; nitrogen oxides; oxidation reduction reaction; spectrometry; stable isotope

Biological interconversions between the various forms of simple forms of simple nitrogen compounds are fundamentally significant processes within the global nitrogen cycle. Metalloproteins within numerous microorganisms play a key role in effecting these transformations and are thus important in controlling the balance of simple nitrogen-containing molecules on earth. Imbalances in the relative concentrations of such compounds in the environment can have significant effects on ecosystems and human health, thus providing impetus for the study of how the controlling metalloproteins operate. Copper-containing enzymes are important in denitrification, a central process in the biological nitrogen cycle whereby several classes of microorganisms utilize oxidized nitrogen compounds as terminal electron acceptors in respiration. Specifically, copper centers in enzymes are involved in several steps in the conversion of nitrate (NO3-) and nitrite (NO2-) to gaseous products (NO, N20 and/or N2). Although there have been advances in understanding aspects of the active site structures of such enzymes, the plausibility of various postulated pathways for the complicated chemistry that they perform has not been determined. In addition, a general lack of knowledge of the fundamental chemistry of copper-NxOy species has hindered attempts to better under-stand how nitrogen oxides bind to and am activated by biological copper centers. The proposed research is designed to address this deficiency by focusing on the synthesis, fun physical and spectroscopic characterization, and detailed study of the reactivity of copper-nitrogen oxide complexes that model the active sites of copper-containing enzymes important in the biological nitrogen cycle. Particular emphasis will be placed on the construction of mononuclear Cu(I) and Cu(II) complexes of NO, N02-, N203 -, and N202-2- supported by multidentate, biomimetic, and sterically hindered ligands. Delineation of the active site features of analogous protein active sites will be accomplished through in-depth studies of the structures and reaction chemistry of these synthetic model compounds.

各种形式的简单形式之间的生物互连 简单的氮化合物在根本上是重要的过程 全球氮循环。 金属蛋白很多 微生物在影响这些转变方面起着关键作用，并且是 因此，对于控制简单含氮的平衡很重要 地球上的分子。 相对浓度的失衡 环境中的化合物会对生态系统产生重大影响 和人类健康，从而为研究如何 控制金属蛋白的操作。 含铜的酶是 在反硝基化中很重要，这是生物学的中心过程 氮循环，几类微生物利用氧化 氮化合物作为呼吸中的末端电子受体。 具体而言，酶的铜中心参与了多个步骤 硝酸盐（NO3-）和亚硝酸盐（NO2-）转化为气态产物 （no，N20和/或N2）。 虽然有 理解此类活动现场结构的各个方面的进步 酶，各种假定途径的合理性 他们执行的复杂化学尚未确定。 在 此外，普遍缺乏对基本化学的了解 铜nxoy物种阻碍了试图更好地底盘的尝试 氮氧化物与生物铜中心结合并激活。 拟议的研究旨在通过集中精力来解决这种缺陷 关于合成，有趣的物理和光谱表征，以及 详细研究铜氮氧化物复合物的反应性 模拟重要的含铜酶的活性位点 生物氮循环。 特别重点将放在 NO，N02-，N203的单核Cu（I）和Cu（II）复合物的构建 - 和N202-2-由多培养基，仿生和在空间上支持 阻碍配体。 类似的主动站点特征的描述 蛋白质活性位点将通过深入研究 这些合成模型化合物的结构和反应化学。