THE COUPLING OF INTERACTION ENERGY TO CONFORMATIONAL DYNAMICS IN PEPCK CATALYSIS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们目前的研究涉及到PEPCK酶突变形式的七个络合物的表征，它们代表了反应坐标上的所有连接状态。我们之前已经为野生型酶确定了这些相同的连接状态，这为我们最近的PNAS出版物提供了基础，这篇论文也在《自然结构和分子生物学》和《1000人的学院》中得到了强调。这些研究代表了先前工作的继续。目前的结构研究旨在支持我们的模型，与最近的研究表明构象动力学在过渡态稳定中的重要性不同，我们目前的生物物理数据与构象动力学在PEPCK催化中的作用是一致的，PEPCK催化在反应催化中间体的稳定中发挥作用，这是一个基态过程。为了支持我们的其他生物物理数据，我们需要获得先前在SSRL为野生型酶确定的相同晶体络合物的结构数据。显然，这些研究的成功完成将为我们对酶的动态特性在催化功能中的作用的基本理解提供大量的见解。

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. Our present studies involve the characterization of seven complexes of a mutant form of the enzyme PEPCK that represent all of the liganded states along the reaction coordinate. We have previously determined these same liganded states for the wild type enzyme that provided the basis for our recent PNAS publication which was also highlighted in Nature Structural and Molecular Biology and the Faculty of 1000. These studies represent a continuation of that previous work. The current structural studies are designed to support our model that states, in contrast to recent studies suggesting the importance of conformational dynamics in transition state stabilization, our current biophysical data is consistent with the role of conformational dynamics in PEPCK catalysis functioning in the stabilization of the reactive catalytic intermediate, a ground state process. In order to support our other biophysical data we need to obtain structural data on the same crystallographic complexes as were previously determined at SSRL for the wild-type enzyme. Clearly the successful completion of these studies will provide a great deal of insight into our fundamental understanding of the role of the dynamic properties of enzymes in catalytic function.