STUDY OF RADIATION DECAY OF PROTEIN CRYSTALS

蛋白质晶体的辐射衰变研究

• 批准号: 7954295
• 负责人: IRIMPAN I MATHEWS
• 金额: $ 1.66万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7954295
• 关键词: Address; Area; Belief; Computer Retrieval of Information on Scientific Projects Database; Data; Data Collection; Data Set; Funding; Gases; Generations; Grant; Institution; Methods; Metric; Photons; Procedures; Proteins; Radiation; Reporting; Research; Research Personnel; Resolution; Resources; Solvents; Source; Synchrotrons; Temperature; Time; United States National Institutes of Health; Writing; infancy; research study; structural biology; synchrotron radiation

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 high-flux beam lines at third generation synchrotrons produce very high intensity x-radiation. Unfortunately, due to decay of the protein crystals in the high intensity beam, the synchrotrons have to use attenuators to reduce the beam intensity. Therefore, beam lines are not utilizing their full potential for protein diffraction experiments. There have been several attempts to study the mechanisms of protein crystal decay. However, this area of study is still in its infancy. The common belief is that the radiation decay is partly due to the effect of the radicals produced by the interaction of x-ray photons with the protein or solvent atoms in the crystal. Researchers have used various procedures like lowering the data collection temperature, incorporating radical scavengers, etc. to reduce the effect of these radicals. The current study tries to address the radiation decay of protein crystals by employing few selected gases as radical scavengers. This is the first study of this kind and the preliminary results underscore the usefulness of this method. Several protein crystals were used for this study. To reduce the effect of crystal size, this study employed crystals with similar sizes. The data sets were collected at three strong beam lines at SSRL. Continuous decay data were taken for several control crystals and for several crystals exposed to a one of the gases. The primary metric used for calculating the damage accrual rate at a given resolution was the change in I/sigma value reported by MOSFLM over the time range of the data set. 115 GB of diffraction data has been collected and analyzed with scripts written specifically for this purpose. Some of the selected gases showed reduced radiation decay.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 第三代同步基因的高频梁线产生非常高的强度X辐射。不幸的是，由于高强度束中蛋白质晶体的衰减，同步加素必须使用衰减器来降低束强度。 因此，光束线没有利用其全部潜力进行蛋白质衍射实验。 已经有几次尝试研究蛋白质晶体衰减的机制。 但是，该研究领域仍处于起步阶段。普遍的信念是，辐射衰减部分是由于X射线光子与晶体中蛋白质或溶剂的相互作用所产生的自由基的作用。 研究人员使用了各种程序，例如降低数据收集温度，结合了自由基清除剂等，以降低这些激进分子的效果。当前的研究试图通过使用一些选定的气体作为根治清除剂来解决蛋白质晶体的辐射衰减。 这是对此类研究的第一个研究，初步结果强调了该方法的实用性。 该研究使用了几种蛋白质晶体。为了降低晶体尺寸的影响，本研究采用了相似尺寸的晶体。 在SSRL处的三个强梁线收集数据集。 连续衰减数据是针对几种对照晶体和暴露于一种气体的几种晶体的。用于计算给定分辨率的损坏应计率的主要度量是MOSFLM报告的I/Sigma值在数据集的时间范围内的变化。已经收集了115 GB的衍射数据，并使用专门为此目的编写的脚本进行了分析。一些选定的气体显示辐射衰减减少。