IN-SITU UV/VIS SPECTROSCOPY FOR MACROMOLECULAR CRYSTALLOGRAPHY

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。该项目的目标是能够同时获得紫外/可见光和红外区的X射线衍射数据和单晶吸收光谱。对紫外(190-400 nm)和可见光(400-800 nm)区域的吸收光谱的分析提供了有关蛋白质在结晶态时的电子状态的信息。在衍射实验期间，将对光谱测量进行分析，以确认氧化还原状态或反应中间体的存在，或潜在地监测可能由光解或X射线产生的降解产物。在BL9-2上安装了单晶显微分光光度计，用于记录测角仪上晶体的光谱。光学元件的定位和第二个显微镜都经过了改进，便于使用。从几个晶体系统记录光谱的尝试为开发过程提供了重要的反馈，特别是定义了定位系统将如何改进，为光学系统增加了额外的自由度，以实现光束的精确对准和聚焦。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to enable the simultaneous acquisition of x-ray diffraction data and single crystal absorption spectra in the UV/Visible and infrared regions. Analysis of the absorption spectrum in the UV (190 - 400 nm) and visible (400 - 800 nm) regions provides information about the electronic state of proteins while in the crystalline state. During diffraction experiments, spectroscopic measurements will be analyzed to confirm the redox state or the presence of reaction intermediates or to potentially monitor degradation products that may be produced either by photolysis or by x-rays. A single crystal microspectrophotometer was set up on BL9-2 to record spectra from crystals on the goniometer. Positioning of the optics and a 2nd microscope were refined for ease of use. Attempts at recording spectra from several crystal systems provided important feedback for the development process, in particular to define how the positioning system will be refined, adding additional degrees of freedom to the optics for precise alignment and focusing of the light beam.