AUTOMATIC CENTERING OF PROTEIN CRYSTALS USING X-RAYS

使用 X 射线自动居中蛋白质晶体

• 批准号: 7721934
• 负责人: S M SOLTIS
• 金额: $ 1.15万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7721934
• 关键词: Algorithms; Characteristics; Computer Retrieval of Information on Scientific Projects Database; Crystallography; Development; Dose; Funding; Grant; Image; Image Analysis; Institution; Methods; Optics; Positioning Attribute; Process; Proteins; Range; Research; Research Personnel; Resources; Sampling; Screening procedure; Source; Testing; United States National Institutes of Health; base; programs

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. In order to fully automate the crystal screening process, methods to automatically align protein crystals to the x-ray beam were refined. The approaches focus on using average I/Sig(I) from low-dose diffraction images taken at various crystal positions in the x-ray beam. These images are analyzed using the image analysis program, DISTL, in order to estimate I/Sig(I), and based on this analysis, a range of parameters are examined and refined in specific algorithms for optimal crystal alignment, determining and using the maximum diffracting power of the crystal rather than the optical center. During the grant year, the algorithm for centering samples was thouroughly tested on each macromolecular crystallography beam line. These tests revealed that different beam characteristics necessitated further refinement of the algorithms, which was accomplished through the development of auto-alignment of the beam to the phi axis of the goniometer.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 为了实现晶体筛选过程的完全自动化，对将蛋白质晶体自动对准 X 射线束的方法进行了改进。 这些方法的重点是使用在 X 射线束中不同晶体位置拍摄的低剂量衍射图像的平均 I/Sig(I)。 使用图像分析程序 DISTL 对这些图像进行分析，以估计 I/Sig(I)，并根据该分析，以特定算法检查和细化一系列参数，以实现最佳晶体排列，确定并使用最大晶体的衍射能力而不是光学中心。在资助年度期间，对每条高分子晶体学光束线对样品居中算法进行了彻底测试。 这些测试表明，不同的光束特性需要进一步改进算法，这是通过开发光束与测角仪 phi 轴的自动对准来实现的。