Spectroscopic Investigations of Metalloenzyme Mechanisms

使用金属中心和/或有机自由基的酶在基础酶中起着许多关键作用。 人体健康的生物化学，其生物组装或酶功能缺陷 与各种疾病有关。中华民国大卫布里特实验室正在使用先进的光谱 技术，如多频电子顺磁共振（EPR），以了解 组装和催化机制的数量这样的金属和自由基中心。许多 参与多电子氧化或还原反应的重要酶使用金属 催化剂中的簇。布里特实验室正在研究这些星团是如何通过 用光谱方法鉴定和询问组装中间体。为 例如，[Fe-Fe]氢化酶使用复杂的多核Fe-S“H-簇”， 含有有机金属Fe-CO和Fe-CN组分，用于催化可逆互变 质子和电子的混合物。大自然如何安全地聚集这样一个中心， 具有潜在危险的CO和CN物质？其他的实验正在解开生物合成 在固氮酶的核心处的复合Fe-S“M-簇”，其可以并入 Mo或V或在其活性部位的额外Fe。我们正在研究一种有趣的 含Cu（II）抗生素，荧光素C。自由基S-腺苷甲硫酮（rSAM）酶进行 许多有趣的反应。在一个有趣的领域，我们正在研究它们如何将肽 核糖体合成和后修饰的肽（RiPP）产物。 调节细胞中的金属成分是至关重要的，我们正在研究一些金属- 结合蛋白参与金属离子螯合和稳态，包括一个新的项目 研究镧系元素在蛋白质中的结合，如羊毛素。我们的目标是一些 诺沃设计了用于详细表征的蛋白质，我们正在开始新的合作 检测人工金属酶和DNA酶的反应性。我们继续合作 并在一些感兴趣的金属酶和自由基酶中提供先进的EPR支持 arena，包括工作低温阱，并与高场EPR表征，瞬态氧- 产生光系统II水氧化酶的S4态。利用定点旋转 标签作为一种工具，我们正在探索一种全蛋白质生化振荡器的动力学， 作为自然界最简单的生物钟。

Enzymes using metal centers and/or organic radicals play many crucial roles in the fundamental biochemistry of human health, with deficiencies in their bioassembly or enzymatic functions associated with various diseases. The R. David Britt laboratory is using advanced spectroscopic techniques, such as multifrequency electron paramagnetic resonance (EPR), to understand the assembly and catalytic mechanism of a number of such metal and radical centers. Many important enzymes involved in multielectron oxidation or reduction reactions employ metal clusters in their catalysis. The Britt laboratory is studying how such clusters are assembled by identifying and interrogating assembly intermediates with their spectroscopic methods. For example, the [Fe-Fe] hydrogenase enzyme uses a complex multinuclear Fe-S “H-cluster”, containing organometallic Fe-CO and Fe-CN components, to catalyze reversible interconversion of H2 with protons and electrons. How does nature safely assemble such a center involving potentially dangerous CO and CN- species? Other experiments are unraveling the biosynthesis of the complex Fe-S “M-cluster” at the heart of the nitrogenase enzyme, which can incorporate Mo or V or an additional Fe in its active site. We are studying the biosynthesis of an interesting Cu(II) containing antibiotic, Fluopsin C. Radical S-adenosylmethione (rSAM) enzymes carry out many interesting reactions. In one interesting area, we are studying how they transform peptides into ribosomally-synthesized and post-translationally modified peptide (RiPP) products. Regulation of metal composition in cells is crucial, and we are examining a number of metal- binding proteins involved in metal ion sequestration and homeostasis, including a new project examining lanthanide binding in proteins such as lanmodulin. We are targeting a number of de novo designed proteins for detailed characterization, and we are starting new collaborations examining the reactivity of artificial metalloenzymes and DNAzymes. We continue to collaborate and provide advanced EPR support in a number of interesting metalloenzyme and radical enzyme arenas, including work to cryotrap, and characterize with high field EPR, the transient oxygen- generating S4 state of the photosystem II water oxidizing enzyme. And using site directed spin labeling as a tool, we are probing the dynamics of an all-protein biochemical oscillator that serves as nature’s simplest circadian clock.