Mossbauer and EPR Studies of Biological Oxygen Activation

化学部的生命过程化学项目获得该奖项，支持卡内基梅隆大学的Ekerard Munck博士对含铁酶和可激活分子氧的合成络合物进行光谱和理论研究。这些研究涉及2，3高原儿茶酸双加氧酶、1，2苯甲酸双加氧酶和甲烷单加氧酶的反应中间体的特征；这些蛋白质中的每一种都是执行基本重要的催化反应的一大类酶的代表。这些研究集中在捕获高氧化态的短寿命(毫秒)中间体，如铁(IV)和铁(V)，并包括低温穆斯堡尔实验和电子顺磁共振实验，辅之以密度泛函理论计算。进一步的研究旨在捕捉水氧化反应中可能的铁(V)中间体，这是无机化学中的一大挑战。从这些研究中获得的信息有望为高氧化态化学的机制提供重要的见解。在哺乳动物和细菌生物体中，许多由含铁酶进行的催化反应都会通过含有作为活性物种的短暂中间体的状态，对于这些中间体，铁原子处于铁(IV)或铁(V)状态，与来自大气氧气的氧基结合。穆斯堡尔谱学是一种强大的工具，可以前所未有的详细地表征这些状态。通过对光谱的分析，可以得到表征铁的氧化态和电子结构的大量参数。这些参数可以通过量子化学方法进行评估，以深入了解这些实体的反应性。化学家可以利用从酶的研究中收集的信息来设计合成络合物，这些络合物要么模仿生物系统，要么执行扩大生物系统范围的功能。这些项目是作为物理学家、化学家和生物化学家之间的合作开展的，为四个合作小组的研究生和博士后研究员提供培训，使他们对生物研究的综合方法有一个广泛的看法。这项研究将成为向卡内基梅隆大学的研究生、明尼苏达大学的七个小组以及2014年宾夕法尼亚州立大学生物无机研讨会的70-80名研究生进行辅导报告的基础。

With this award, the Chemistry of Life Processes Program in the Chemistry Division supports Dr. Eckard Munck from Carnegie Mellon University to conduct spectroscopic and theoretical studies of iron-containing enzymes and synthetic complexes that activate molecular oxygen. The studies involve characterization of reaction intermediates of the enzymes 2,3 homoprotocatechuate dioxygenase, 1,2 benzoate dioxygenase and methane monooxygenase; each of these proteins is a representative of a large class of enzymes that carry out catalytic reactions of fundamental importance. The studies focus on trapping short-lived (milliseconds) intermediates in high oxidations states such as iron(IV) and iron(V and involve low temperature Mossbauer and Electron Paramagnetic Resonance experiments, complemented by density functional theory calculations. Further studies are aimed at trapping putative iron(V) intermediates in water oxidation reactions, one of the great challenges in inorganic chemistry. Information gained from these investigations is expected to provide crucial insights into the mechanisms of high oxidation state chemistry.Many catalytic reactions carried out by iron-containing enzymes in mammalian and bacterial organisms pass through states that contain as reactive species short-lived intermediates for which the iron atom is in an iron(IV) or iron(V) state bound to an oxo group derived from atmospheric oxygen. Mossbauer spectroscopy is a powerful tool to characterize these states in unprecedented detail. The spectra can be analyzed to yield a large number of parameters that characterize the oxidation state and the electronic structure of the iron. These parameters can be evaluated by quantum chemical methods to yield insights into the reactivity of these entities. Information gleaned from studies of the enzymes can be used by chemists to design synthetic complexes that either mimic the biological systems or perform functions that extend the range of the latter. The projects are carried out as collaborations between physicists, chemists and biochemists, providing training for graduate students and postdoctoral fellows of four collaborating groups as they acquire a broad perspective of an integrative approach to biological research. The research will be the basis of tutorial presentations to graduate students at Carnegie Mellon University, seven groups at the University of Minnesota as well to 70-80 graduate students at the 2014 Penn State Bioinorganic Workshop.