Acquisition of a Spectrofluorometer

已提供资金购买一台高性能静态荧光分光光度计，供一组调查人员共用。该仪器将用于四个涉及蛋白质的不同项目，每个项目都利用荧光作为一种技术。荧光强度测量将被用作监测蛋白质-蛋白质和蛋白质-核酸相互作用、配体诱导的构象变化以及荧光体对猝灭剂的可及性等过程的一种手段。荧光各向异性的测量也将被用于研究蛋白质的结合和构象变化。荧光能量转移将被用作“光谱标尺”来测量蛋白质上的位置分离。上述类型的研究要求仪器具有高灵敏度和稳定性、低本底和提供校正光谱的能力。这些单独的项目涉及钙结合调节蛋白钙调蛋白和肌钙蛋白C的性质和相互作用，木瓜酶催化部位的性质，核酸解离蛋白的特征，以及介导DNA几何结构变化的拓扑异构酶的性质。分子生物学的一个中心目标是阐明特定分子的结构，并确定它们的化学特性如何影响它们的活性。一种方法是荧光光谱学，它提供关于分子亚群和分子-分子相互作用的数据。这类信息在最基本的层面上解释了生物过程。

Funds have been provided for the purchase of a high performance static spectrofluorometer for shared use by a group of investigators. The instrument will be used for four different projects involving proteins, each of which utilizes fluorescence as a technique. Fluorescence intensity measurements will be used as a means of monitoring such processes as protein-protein and protein-nucleic acid interactions, ligand-induced conformational changes, and accessibility of fluorophors to quencher. Measurements of fluorescence anisotropy will also be used to study protein associations and conformational changes. Fluorescence energy transfer will be employed as a "spectroscopic ruler" to measure the separation of sites on a protein. Studies of the above kinds require an instrument with high sensitivity and stability, low background, and capability of providing corrected spectra. The individual projects are concerned with the properties and interactions of the Ca2+-binding regulatory proteins calmodulin and troponin C, the nature of the catalytic site of papain, the characteristics of nucleic acid-unwinding proteins, and the properties of the topoismerase enzymes which mediate alterations in the geometry of DNA. A central goal of molecular biology is to elucidate the structure of specific molecules and determine how their chemical characteristics influence their activity. One approach is fluorescence spectroscopy, which provides data about molecular subgroups and molecule-molecule interactions. This kind of information explains biological processes at their most basic level.