RUI: Mossbauer Studies of Iron Containing Enzyme Active Sites and Model Complexes

通过这个奖项，化学学部的生命过程化学项目和分子与细胞生物科学部的分子生物物理学项目支持乌尔西纳学院的Codrina V. Popescu博士与本科生一起进行穆斯堡尔光谱学研究。研究范围从小分子铁（Fe）化合物的研究到蛋白质中新铁位点的探索。本研究的预期科学成果是：(1)阐明新型铁基氢电催化剂的电子结构和氢化酶模型，包括缺乏光谱基准的低自旋Fe(I)；(2)氢化酶和其他仿生化合物模型配合物结构和光谱变化的相关性；(3)研究了花青树双功能血红蛋白过氧化物酶脱盐过氧化物酶活性位点及环裂双加氧酶催化中间体模型。铁是生物系统中最丰富的过渡金属。铁蛋白和铁酶参与生命过程，如氧化、解毒、氢和氮代谢。穆斯堡尔光谱学可以深入了解铁化合物的电子结构，通常允许我们直接阐明酶活性位点的性质，或者通过探测可能用作催化剂的小分子模型。基础研究中的前沿问题对环境问题有影响，例如对清洁能源的需求和处理污染。从穆斯堡尔光谱的细节中，我们试图了解铁是如何被用来以无害环境的方式完成各种各样的化学壮举的。这些跨学科项目目前对基础科学和潜在技术应用具有广泛的兴趣，从替代燃料（氢化酶模型复合物）到催化（仿生学）和环境生物修复（去氢过氧化物酶）。通过其跨学科的合作性质，这项研究对来自其他四个机构的合作者的项目产生了影响，并允许乌尔西纳学院的本科生与来自这些其他研究小组的学生和教师进行互动。这项研究促进了导师和学生之间的密切关系，他们积极参与科学发现的所有步骤，从产生假设到解释阐明新电子结构所需的光谱参数。这个本科研究培训和教育项目通过高级学位培养学生的成长和独立性，为他们在STEM教学和研究领域的职业生涯做好准备。它还为各种各样的学生提供跨学科项目，在这些项目中，动手光谱学应用于当前的科学问题，并在外部演示和出版物中得到结果。

With this award, the Chemistry of Life Processes Program in the Chemistry Division and the Molecular Biophysics program in the Division of Molecular and Cellular Biosciences (MCB) support Dr. Codrina V. Popescu at Ursinus College for research in Mossbauer spectroscopy conducted with undergraduate students. Research ranges from studies of small-molecule iron (Fe) compounds to the exploration of novel Fe sites in proteins. The expected scientific outcomes of this research are: (1) elucidation of electronic structures for new iron-based hydrogen electrocatalysts and models for the hydrogenase enzymes, including low-spin Fe(I), for which spectroscopic benchmarks are scarce; (2) correlation of structural and spectroscopic changes in model complexes for the hydrogenases and other biomimetic compounds; (3) characterization of the active site of the dual function hemoglobin-peroxidase enzyme dehaloperoxidase from A. ornata and of models for catalytic intermediates in ring-cleaving dioxygenases. Iron is the most abundant transition metal in biological systems. Iron proteins and enzymes are involved in life processes, such as oxidation, detoxification, hydrogen and nitrogen metabolism. Mossbauer spectroscopy can bring insight into the electronic structure of iron compounds, often allowing us to elucidate the nature of the active sites of enzymes directly, or by probing small-molecule models, which may be used as catalysts. Frontier problems in fundamental research have implications for environmental problems, such as the need for cleaner energy sources and dealing with pollution. From details of Mossbauer spectra we are attempting to learn how iron is used to perform vastly different feats of chemistry in environmentally benign ways. These interdisciplinary projects are of broad current interest for fundamental science and potential technological applications, from alternative fuels (hydrogenase model complexes) to catalysis (biomimetics), and environmental bioremediation (dehaloperoxidase). Through its interdisciplinary collaborative nature, this research has impact on the projects of collaborators from four other institutions and allows the undergraduates at Ursinus College to interact with students and faculty from these other research groups. The research promotes a close relationship between mentor and students, who are active in all the steps of scientific discovery, from generating hypotheses to interpreting the spectroscopic parameters needed to elucidate new electronic structures. This undergraduate research training and education program fosters the students' growth and independence through advanced degrees, preparing them for STEM careers in teaching and research. It also provides interdisciplinary projects for a diverse pool of students, in which hands-on spectroscopy is applied to current scientific problems and results in external presentations and publications.