MRI: Acquisition of a Circular Dichroism Spectrometer

根据化学主要研究仪器项目授予的这一奖项，密苏里大学圣路易斯分校的Michael Nichols教授将获得一台具有吸光度和荧光能力、温度控制系统以及扫描发射单色仪的温控、止流圆二色（CD）分光偏振仪。该提案旨在加强各级的研究和教育，特别是在以下领域：(a)蛋白质折叠和自组装的早期阶段；(b)蛋白质在空气-水界面的自组装；(c)转铁蛋白释放；(d)激素敏感脂肪酶的结构方面；(e)生长素稳态相关蛋白的突变研究；(f) Puf蛋白突变体的研究；(g) dna -配体相互作用；(h)脱氧核酶和DNA适体；(1)核酸复合物的结构特征；(j)肽类合成离子通道；(k)碳水化合物配位；(l)手性-金属配合物。圆二色分光光度计将产生光谱数据，提供有关分子结构的信息，特别是生物分子的构象，如核酸、蛋白质和酶。其测量原理是基于光学活性样品（如DNA双螺旋结构中的样品）对左右圆偏振光的微分吸收。停止流动系统允许快速混合样品，从而获得用于化学动力学研究的实时数据。一般来说，在止流光谱仪中，酶促反应是通过打开阀门，然后注射酶和底物来开始的。混合量由酶、底物和停止注射器柱塞的作用控制。该仪器将提供研究和实验室培训的分析技术，允许测量有机和无机分子的物理性质的研究生和本科生以及博士后研究员。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.