STRUCT & FUNCT OF MUTANT VERSIONS OF ALKALINE PHOSPHATASE FROM ECOLI

这个项目的目标是加深对 蛋白质结构与功能关系的研究进展 以碱性磷酸酶为模型体系。这种酶的功能 是催化磷酸酯的非特异性水解，而 缺乏这种酶的活性会导致致命的遗传性 疾病低磷症。哺乳动物的碱性磷酸酶 与相应的细菌酶密切相关，而该酶 从大肠杆菌中分离出来的细菌已经成为研究所有 碱性磷酸酶。在PSC的Y-MP C90上的额外时间是 是为了继续这个项目而被要求的。这涉及到 使用XploR程序对X-射线单晶数据进行精炼 已有数据的酶的突变版本，以及 至少还有四个人的数据将在短期内收集。我们 还将使用XploR和CHARMM进行分子动力学 对酶的突变版本进行计算以帮助 了解它们的不同寻常的特性。当地的计算机设施有 无法在合理的时间内进行这些计算。 然后，将在引起的功能变化之间建立关联 通过氨基酸取代和化合物的三维结构 突变的酶。这项工作不仅对 对这一特殊系统的理解，但更重要的是 阐述了酶催化的一般概念，以及酶催化的作用 蛋白质中的金属，并提供了一种分子解释 基因间互补。

The goals of this project are to acquire a deeper understanding of the relationship between protein structure and function by using alkaline phosphatase as a model system. The function of this enzyme is to catalyze the nonspecific hydrolysis of phosphate esters, and the lack of the activity of this enzyme results in the fatal hereditary disease hypophosphatasia. Alkaline phosphatase from mammals is closely related to the corresponding bacterial enzyme, and the enzyme from Escherichia coli has become the model for the study of all alkaline phosphatases. Additional time on the Y-MP C90 at PSC is being requested in order to carry on with this project. This involves using the program XPLOR to refine the x-ray crystallography data on mutant versions of the enzyme for which data is already available, and at least four others for which data will be collected shortly. We will also use of XPLOR and CHARMM to carry out molecular dynamics calculations on mutant versions of the enzyme in order to help understand their unusual properties. Local computer facilities are not capable of carrying out these calculations in reasonable times. Correlations will then be made between the functional changes induced by the amino acid substitution and the three-dimensional structure of the mutant enzymes. This work will not only be important for the understanding of this particular system, but more importantly for formulating general concepts about enzyme catalysis, and the function of metals in proteins, and providing a molecular explanation for intergenic complementation.