MRI: Acquisition of a Spectropolarimeter for Circular Dichroism and Magnetic Circular Dichroism Experiments

MRI：获取用于圆二色性和磁圆二色性实验的分光偏振计

• 批准号: 0820965
• 负责人: James Larrabee
• 金额: $ 7.67万
• 依托单位: Middlebury College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0820965&HistoricalAwards=false
• 关键词: MRI; Acquisition; Spectropolarimeter; Circular; Dichroism

The Department of Chemistry at Middlebury College will acquire a spectropolarimeter with this award from the Major Research Instrumentation (MRI) program. It will be coupled to a variable field magnet to enable magnetic circular dichroism (MCD) as well as circular dichroism (CD) measurements. Studies by the principal investigator (PI) will utilize variable temperature, variable field magnetic circular dichroism to determine the strength of the magnetic coupling in a series of carboxylate-bridged Co(II) dimer complexes and enzyme active sites which contain dinuclear Co(II). This will provide a more detailed picture of the electronic ground state structure of this active site motif commonly found in nature. MCD will be used by the co-PI to perform exploratory experiments on the interactions of Ru(III) complexes with DNA analogues. Two additional Middlebury biochemistry professors will use the instrument to collect CD data for protein secondary structure analysis.A circular dichroism spectropolarimeter will produce circular dichroism spectral data that provides information on molecular structure and especially the conformations of biomolecules such as proteins, enzymes and nucleic acids. In magnetic circular dichroism, chirality is induced by a strong magnetic field applied parallel to the direction of light propagation, a phenomenon known as the Faraday effect. The behavior of MCD intensity with temperature and field strength is dependent on the electronic ground state of the metal. Thus MCD is a sensitive probe of the electronic structure associated with paramagnetic metals ions in small complexes and protein active sites. The instrument will be used in research by undergraduate students. This training will prepare students to utilize this sophisticated technique in various careers, especially in chemical, biological and health related fields.

米德尔伯里学院化学系将从主要研究仪器（MRI）计划中获得该奖项的分光偏振仪。 它将被耦合到一个可变场磁铁，使磁性圆二色性（MCD）以及圆二色性（CD）测量。 主要研究者（PI）的研究将利用可变温度，可变场磁性圆二色性来确定一系列羧酸根桥接的Co（II）二聚体络合物和含有双核Co（II）的酶活性位点中的磁耦合强度。这将提供一个更详细的图片的电子基态结构的这种活性位点基序在自然界中常见。 MCD将由co-PI用于对Ru（III）络合物与DNA类似物的相互作用进行探索性实验。另外两名Middlebury生物化学教授将使用该仪器收集蛋白质二级结构分析的CD数据。圆二色性分光偏振仪将产生圆二色性光谱数据，提供有关分子结构的信息，特别是蛋白质，酶和核酸等生物分子的构象。 在磁性圆二色性中，手性是由平行于光传播方向施加的强磁场引起的，这种现象称为法拉第效应。MCD强度随温度和场强的变化与金属的电子基态有关。因此，MCD是与小复合物和蛋白质活性位点中的顺磁性金属离子相关的电子结构的灵敏探针。 该仪器将用于本科生的研究。 这项培训将帮助学生在各种职业中利用这种复杂的技术，特别是在化学，生物和健康相关领域。