IN-SITU UV/VIS SPECTROSCOPY AT HELIUM TEMPERATURES

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 在近液氦温度下，探索了在紫外/可见光区同时获得X射线衍射数据和单晶吸收光谱。 在BL 12 -2上安装了一台单晶显微分光光度计，记录光谱。原地？从安装在测角仪上的晶体上。 用液氦冷流系统代替了传统的液氮冷流系统。 在衍射实验期间，分析光谱测量以确认酶晶体的金属位点的氧化还原状态。 在80 K和~15 K下测量了辐射诱导的光还原速率。 基于这些测量，还原速率在较低温度下降低2-3倍。

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 simultaneous acquisition of x-ray diffraction data and single crystal absorption spectra in the UV/Visible region was explored at near liguid helium temperatures. A single crystal microspectrophotometer was set up on BL12-2 to record spectra ?in-situ? from crystals mounted on the goniometer. The conventional liquid nitrogen cold stream was replaced by a liquie helium coldstream system. During diffraction experiments, spectroscopic measurements were analyzed to confirm the redox state of the metal site of the enzyme crystal. Rates of radiation-induced photo-reduction were measured at 80 K and ~15 K. Based on these measurements, the rate of reduction was reduced by a factor of 2-3 at the lower temperature.