MODELING COPPER PROTEIN--NITROGEN OXIDE INTERACTIONS

不同形式的简单形式之间的生物转化 简单的含氮化合物是从根本上意义重大的过程 全球氮循环。众多金属蛋白中的 微生物在影响这些转化中起着关键作用，并且 因此在控制简单含氮的平衡方面很重要 地球上的分子。这类物质的相对浓度不平衡 环境中的化合物可能会对生态系统产生重大影响 和人类健康，从而为研究人类如何 控制金属蛋白起作用。含铜的酶是 在反硝化中很重要，反硝化是生物脱氮的核心过程 几类微生物利用氧化的氮循环 氮化物在呼吸作用中作为末端电子受体。 具体地说，酶中的铜中心参与了几个步骤 硝酸盐(NO3-)和亚硝酸盐(NO2-)转化为气态产物 (否，n20和/或n2)。尽管已经有了 关于这类分子活性中心结构的研究进展 酶，各种假设的途径的可信性 它们所表现出的复杂化学作用尚未确定。在……里面 此外，普遍缺乏对基础化学的知识 铜-NxOy物种阻碍了更好地理解 氮氧化物与生物铜中心结合并被其激活。 这项拟议的研究旨在通过聚焦于 关于合成，有趣的物理和光谱表征，和 详细研究了铜-氮氧化物络合物的反应性 对含铜酶的活性部位进行建模，这些酶在 生物氮循环。特别强调的将是 NO、N02-、N203单核铜(I)和铜(II)配合物的合成 -和N202-2-由多齿、仿生和立体支撑 受阻的配体。类似物活动部位特征的圈定 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。

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.