MRI: Acquisition of a Circular Dichroism Spectrometer

凭借化学专业研究仪器计划的这一奖项，来自密苏里州圣刘易斯大学的Michael Nichols教授将获得一台具有吸光度和荧光功能的温控停流圆二色性（CD）分光偏振仪，以及一台扫描发射单色仪。该提案旨在加强各级的研究和教育，特别是在以下领域：（a）蛋白质折叠和自我组装的早期阶段;（B）空气-水界面的蛋白质自我组装;（c）转铁蛋白铁的释放;（d）激素敏感脂肪酶的结构方面;（e）参与生长素体内平衡的蛋白质的突变研究;（f）Puf蛋白突变体研究;（g）DNA-配体相互作用;（h）脱氧核酶和DNA适体;（i）核酸复合物的结构特征;（j）基于肽的合成离子通道;（k）碳水化合物端基异构体分配，和（l）手性-金属络合物。圆二色性分光光度计将产生光谱数据，其提供关于分子结构的信息，特别是生物-分子如核酸、蛋白质和酶。原理测量是基于光学活性样品（如DNA双螺旋中的样品）对左右圆偏振光的差分吸收。停流系统允许样品的快速混合，从而允许获得用于化学动力学研究的真实的时间数据。一般而言，在停流光谱仪中，通过打开阀门然后注入酶和底物来启动酶促反应。通过酶、底物和停止注射器柱塞的作用控制混合量。该仪器将为研究生和本科生以及博士后研究员提供分析技术方面的研究和实验室培训，以便测量有机和无机分子的物理特性。CD分光光度计将被整合到化学和生物化学学生的培训中，用于分子间相互作用，几何异构体和蛋白质结构的研究。

With this award from the Chemistry Major Research Instrumentation Program, Professor Michael Nichols from University of Missouri Saint Louis will acquire a temperature-controlled, stopped-flow circular dichroism (CD) spectropolarimeter with absorbance and fluorescence capabilities and temperature control system as well as a scanning emission monochromator. The proposal is aimed at enhancing research and education at all levels, especially in areas such as (a) early stages of protein folding and self-assembly; (b) protein self-assembly at the air-water interface; (c) transferrin iron release, (d) structural aspects of hormone sensitive lipase; (e) mutational studies of proteins involved in auxin homeostasis; (f) studies of Puf proteins mutants; (g) DNA-ligand interactions; (h) deoxyribozymes and DNA aptamers; (i) structural features of nucleic acid complexes; (j) peptide-based synthetic ion channels; (k) carbohydrate anomeric assignment, and (l) chirality-at-metal complexes.A circular dichroism spectrophotometer will produce spectral data that provide information on molecular structure and especially the conformations of bio-molecules such as nucleic acids, proteins, and enzymes. The principle measurement is based on differential absorption of left and right circularly polarized light by optically active samples such as those in the double helix of DNA. The stop-flow system allows rapid mixing of samples allowing the acquisition of real time data for the study of chemical kinetics. In general, in a stopped flow spectrometer the enzymatic reaction is initiated by opening of valves followed by injection of the enzyme and substrate. The quantities mixed are controlled by the action of the enzyme, substrate, and stop syringe plungers. The instrument will provide research and laboratory training in analytical techniques that allow measurement of physical properties of organic and inorganic molecules to graduate and undergraduate students as well as postdoctoral fellows. The CD spectrophotometer will be integrated into training of students in Chemistry and Biochemistry for the study of intermolecular interactions, geometric isomers and protein structure.