MRI: Acquisition of a Circular Dichroism Spectrometer

密苏里圣路易斯大学的Michael Nichols教授获得了化学专业研究仪器计划颁发的这一奖项，他将获得一台温控、停流圆二色(CD)光谱偏振仪，具有吸收和荧光能力、温度控制系统以及扫描发射单色仪。该提案旨在加强所有各级的研究和教育，特别是在下列领域：(A)蛋白质折叠和自组装的早期阶段；(B)蛋白质在空气-水界面上的自组装；(C)转铁蛋白铁的释放；(D)激素敏感脂肪酶的结构方面；(E)生长素稳态所涉及的蛋白质的突变研究；(F)Puf蛋白质突变的研究；(G)DNA-配体相互作用；(H)脱氧核酶和DNA适配子；(I)核酸复合体的结构特征；(J)基于多肽的合成离子通道；(K)碳水化合物的异常指定和(L)手性金属络合物。圆二色分光光度计将产生提供分子结构信息的光谱数据，特别是生物分子的构象信息，如核酸、蛋白质和酶。测量原理是基于光学活性样品对左右圆偏振光的差示吸收，例如DNA双螺旋中的样品。停流系统允许快速混合样品，从而能够获取用于化学动力学研究的实时数据。一般来说，在停流光谱仪中，酶反应是通过打开阀门，然后注入酶和底物来启动的。混合量由酶、底物和止动注射器柱塞的作用控制。该仪器将提供分析技术方面的研究和实验室培训，使研究生和本科生以及博士后研究员能够测量有机和无机分子的物理性质。CD分光光度计将被整合到化学和生物化学学生的培训中，用于研究分子间相互作用、几何异构体和蛋白质结构。

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.