STRUCTURE DETERMINATION ON THE LYMPHOKINE GM-CSF

描述：(改编自申请人摘要)。这样做的目的是 研究是为了获得关于人类三维结构的知识， 猿猴和小鼠粒细胞巨噬细胞集落刺激因子 (GM-CSF)。研究人员声称已经获得了人类GM-CSF晶体 它的衍射率至少为2.5A，非常适合结构研究 在高分辨率下。猿猴和老鼠的形态还没有产生 具有X射线质量的晶体。X射线结晶学技术将是 应用于这三种蛋白质的晶体中。使用重原子 同构替换法和/或多波长反常 色散技术，其中一个结构将在3A时求解 分辨率或更好，以允许跟踪多肽链的路径和 模型建筑。在这点上，初始阶段将通过使用 可能导致的三倍信息冗余 非晶体对称性。然后，分子置换方法将 用这个模型来求解另外两个结构和 特别设计的突变体。所有结构都将在 尽可能高的分辨率，以确保模型的最大精度。这个 结构知识将与以下结果相结合使用 诱变实验和其他结构/功能研究 GM-CSF活性所需的结构特征。调查人员 相信这样的信息将导致基于结构的设计 激动剂和拮抗剂分子，它还将使人们深入了解 已知的异质性的实际意义在 重组GM-CSF分子与导向定点突变 旨在消除结构异质性和改善结构的实验 药理特性。

DESCRIPTION: (Adapted from Applicant's Abstract). The objective of this research is to gain knowledge of the three-dimensional structures of human, simian and murine granulocyte macrophage-colony stimulating factors (GM-CSF). The investigators claim to have obtained human GM-CSF crystals which diffract to at least 2.5 A and are well suited to structure studies at high resolution. The simian and murine forms have not yet produced X-ray quality crystals. The technique of X-ray crystallography will be applied to crystals of each of these three proteins. Using heavy atom isomorphous replacement methods and/or the multiple wavelength anomalous dispersion technique, one of the structures will be solved at 3 A resolution or better, to allow tracing of the path of the peptide chain and model building. At this point initial phases will be improved by use of the probable three-fold informational redundancy caused by the non-crystallographic symmetry. The molecular replacement method will then use this model to solve the other two structures and those of specifically-designed mutants. All structures will be refined at the highest resolution possible to ensure maximum accuracy of the models. The structural knowledge will be used in combination with results from mutagenesis experiments and other structure/function studies to map the structural features required for GM-CSF activity. The investigators believe that such information will lead to the structure-based design of agonist and antagonist molecules and that it will also give insight into the practical implications of heterogeneity known to be present in recombinant GM-CSF molecules and guide site-directed mutagenesis experiments aimed at removing structural heterogeneities and improving pharmacological properties.