Spectroscopic Studies of Molybdoenzymes & Models

关于钼辅因子(MOCO)的最终步骤，在知识库中存在着根本的空白 生物合成和硫化--钼蛋氨酸亚砜还原酶如何利用吡喃蝶呤二硫杂环戊烯 辅因子在催化中的组成(MPT)，以及非MPT配体在催化循环中的作用 二甲基亚砜还原酶家族酶。我们的长期目标是了解几何学和电子学 结构贡献为吡喃蝶呤钼的酶活性和功能提供了正向作用 对人类健康质量的影响。我们的主要目标是确定关键的MOCO成熟，运输 和硫化步骤，定义了MSRP的机制和MPT在MSR介导的催化中的作用，以及 了解DMSOR家族酶中主要顺磁中间体的电子结构 通过详细的成键、光谱和反应坐标增强的组合光谱方法 计算。中心假设是蛋白质的特定几何和电子结构改变- 结合的MOCO定义了催化的独特反应。这项研究的基本原理是，一个全面的 了解钼的成熟和运输，钼和MPT在MSR催化中的复杂相互作用， 顺磁性DMSOR家族中间体的性质将为疾病状态和 对人类健康有积极影响。我们将检验我们的中心假设，以实现这些目标 通过成功地追求三个具体目标1)了解MOCO的成熟、运输、 和硫化反应，2)确定电子结构对MSRP催化的贡献，3)确定电子结构 以及DMSOR家族酶中顺磁中间体的几何结构。拟议的研究是 其方法具有创新性，因为我们集成了结构、多组分光谱和 关于模型和酶的计算研究，以解决与最后阶段有关的关键问题 在MoCO生物合成和硫化过程中，Mo催化氧化损伤蛋白质的修复机制，以及 吡喃蝶呤钼酶催化中MPT与氨基酸连接的协同作用。这有 引发了对钼酶领域长期存在的问题的新见解，有效地开辟了 今后在这一领域的工作。这项拟议的研究具有重要意义，因为它将影响和促进我们的理解 钼酸盐插入和翻译后硫化过程，硫和钼的转移，钼酶 氧化损伤蛋白质的介导性抢救及氨基酸和吡喃蝶呤二硫杂环戊烯配体的作用 在钼酶催化中。

There exist fundamental gaps in the knowledge base regarding the final steps of molybdenum cofactor (Moco) biosynthesis and sulfuration, how the Mo methionine sulfoxide reductase utilizes the pyranopterin dithiolene component (MPT) of the cofactor in catalysis, and the role of non-MPT ligands in the catalytic cycles of dimethylsulfoxide reductase family enzymes. Our long-term goal is to understand geometric and electronic structure contributions to pyranopterin molybdenum enzyme reactivity and function in order to provide a positive impact on the quality of human health. Our primary objectives are to determine critical Moco maturation, transport and sulfuration steps, define the mechanism of MsrP and the role of the MPT in Msr mediated catalysis, and understand the electronic structure of key paramagnetic intermediates in DMSOR family enzymes using a combined spectroscopic approach augmented by detailed bonding, spectroscopic, and reaction coordinate calculations. The central hypothesis is that specific geometric and electronic structure modifications of protein- bound Moco define the unique reactions catalyzed. The rationale for this research is that a comprehensive understanding of Moco maturation and transport, the complex interplay between Mo the MPT in Msr catalysis, and the nature of paramagnetic DMSOR family intermediates will provide new insights into disease states and have a positive impact on human health. We will test our central hypothesis in order to accomplish the objectives of this proposal through the successful pursuit of three Specific Aims 1) Understand Moco maturation, transport, and sulfuration, 2) Determine electronic structure contributions to MsrP catalysis, 3) Determine the electronic and geometric structure of paramagnetic intermediates in DMSOR family enzymes. The proposed research is innovative in its approach because we have integrated structural, multicomponent spectroscopic, and computational investigations on models and enzymes to address critical questions concerning the final stages of Moco biosynthesis and sulfuration, Mo catalyzed repair mechanisms for oxidatively damaged proteins, and the synergistic interactions between MPT and amino acid ligation in pyranopterin Mo enzyme catalysis. This has led to new insight into long-standing questions in the molybdoenzyme field, effectively opening new horizons for future work in this area. The proposed research is significant since it will impact and advance our understanding of molybdate insertion and post-translational sulfuration processes, sulfur and Moco trafficking, molybdoenzyme mediated rescue of oxidatively damaged proteins, and the roles of amino acid and pyranopterin dithiolene ligands in molybdoenzyme catalysis.