RUI: Determination of Magnetic Exchange Coupling in Carboxylate-Bridged Binuclear Co(II) by Magnetic Circular Dochroism

詹姆斯Larrabee，化学系，明德学院，是由化学系的无机，生物无机和有机化学计划的支持，以确定磁交换耦合，J，在一系列羧酸桥双核钴（II）配合物使用可变场，变温磁性圆二色性（VTVH MCD）。最终目标是开发VTVH MCD作为一种工具，以监测双核Co（II）酶的活性位点的变化，当它们与底物，底物类似物和/或抑制剂相互作用时发生。一系列双核Co（II）模型化合物将被研究，以确定决定J的大小的因素。大肠杆菌、Co（II）-取代的血红蛋白和Co（II）-取代的氨肽酶，它们中的每一个都含有一个羧基桥联的双核Co（II）位点，然后将被检查。最后，模型复合物和酶之间的相关性将试图确定J的大小是否在酶的功能中起作用，以及J的变化是否可以用来探测酶的功能。本研究旨在开发一种新的工具，VTVH MCD，以研究这些金属网站在生物系统中的功能。此外，它将加深对影响Co（II）离子之间相互作用强度的因素的理解，这些因素可能与分子磁性有关。这项研究将在一个主要的本科院校，米德尔伯里学院，与本科生进行。这种类型的研究经验将鼓励本科生追求科学事业。

Dr. James Larrabee, Chemistry Department, Middlebury College, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division to determine the magnetic exchange coupling, J, in a series of carboxylate bridged binuclear Co(II) complexes using variable-field, variable temperature magnetic circular dichroism (VTVH MCD). The ultimate goal is to develop VTVH MCD as a tool to monitor changes in the active sites of binuclear Co(II) enzymes that occur when they interact with substrates, substrate analogs and/or inhibitors. A series of binuclear Co(II) model compounds will be investigated to determine the factors that determine the magnitude of J. The enzymes methionyl aminopeptidase from E. coli, Co(II)-substituted hemerythrin, and Co(II)-substituted aminopeptidase, each of which contains a carboxylatebridged binuclear Co(II) site, will then be examined. Ultimately, correlations between the model complexes and the enzymes will be attempted in order to ascertain if the magnitude of J plays a role in the function of the enzyme and if changes in J can be used to probe enzyme function.The carboxylatebridged dimetallic active site is a common structural motif in proteins and enzymes. This investigation aims to develop a new tool, VTVH MCD, to investigate how these metal sites function in biological systems. In addition, it will deepen the understanding of factors that affect the strength of the interactions between Co(II) ions, which can have relevance to molecular magnetism. The research will be conducted at a predominantly undergraduate institution, Middlebury College, with undergraduate students. This type of research experience will encourage undergraduates to pursue careers in science.