STUDIES OF CRYO-COOLING AND CATALYTIC MECHANISM IN E COLI BETA-GALACTOSIDASE

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。描述了三个涉及大肠杆菌β-半乳糖苷酶的实验，旨在解决三个广泛相关的主题。首先是通过了解低温冷却引起的β-半乳糖苷酶晶体中的再堆积来提高我们对低温冷却的基础知识。其次是了解堆积作用力如何通过表征不对称单位中不同亚基与配体结合的差异来调节酶活性。第三是了解构象开关在β-半乳糖苷酶活性中的作用，以及堆积力量如何影响这种开关。每个实验在原理上都很简单，但考虑到单位电池的大小，技术上要求很高。变异体和络合物的结构将被确定到1.1？分辨率。

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. Three experiments are described involving E. coli beta-galactosidase designed to address three broadly related topics. First is to improve our basic knowledge about cryocooling by understanding the cryocooling induced repacking in crystals of beta-galactosidase. Second is to understand how packing forces modulate enzyme activity by characterizing differences in ligand binding to separate subunits in an asymmetric unit. And third is to understand the role of a conformational switch in the activity of beta-galactosidase and how packing forces affect this switch. Each experiment is straightforward in principle, but technically demanding given the large size of the unit cell. Structures of variants and complexes will be determined up to 1.1 ¿¿resolution.