DYNAMICS IN ENZYME ACTION

本方案项目提案涉及阐明以下方面的作用： 多肽链动力学中的催化机理 通过酶。该提案的总体目标是探讨假设 多肽链的动力学强烈地影响着 介导酶的作用，可能是一个必要的因素， 实现高周转率以及精致的特异性， 反应.该计划项目分为4个项目，都紧紧围绕 围绕这个长远目标，紧密地联系在一起。两个非常 不同的酶系统，二氢叶酸还原酶（DHFR）和金属- β-内酰胺酶，可能被选择进行深入研究，希望 这两个系统所获得的结果可以概括为 提案的指导假设。前两个项目是关注 用实验方法测定多肽链动力学， NMR弛豫和其他方法。项目1（体育）Wright，P.I.）将重点 利用核磁共振弛豫和其他方法研究动力学。项目1（体育） Wright，P.I.）将重点放在动态DHFR在二元和三元 与底物、抑制剂和辅因子的复合物，以及突变体 基于初步的核磁共振动力学 测量.项目2最终将遵循类似的协议 （H，J. Dyson，P.I.）金属β-内酰胺酶初步目标 项目将涉及共振分配和与结构的相关性， 以及15 N和13 C弛豫的动力学估计， 从酰胺质子氢交换率。项目3（S. J. Benkovic，P.I.） 将利用项目1和2中提供的信息设计场地- 这两种酶的定向突变体和抑制剂。这些信息 除了对酶至关重要外，DHFR也是重要的药物靶点， 抗癌治疗和金属β-内酰胺酶，因为它是一个主要的 病原菌的抗生素耐药性的组成部分。项目4（D.A. 案例P.1，C.L.布鲁克斯，三，共同P. I.）提供了基本的理论 项目的基础。根据项目提供的资料 1、2和3，项目4将尝试模拟反应途径， 与结构，动态和动力学信息，提供了潜在的 对于原子反应机制的基本理解， 电子水平。这些项目共同构成了一项重点工作， 了解酶催化，结合新的想法，动力学的 所述多肽很可能是所述多肽的组成部分和重要组分， 整个过程

This Program Project proposal concerns the elucidation of the role of polypeptide chain dynamics in the mechanism in the mechanism of catalysis by enzymes. The overall goal of the proposal is to explore the hypothesis that polypeptide chain dynamics strongly influence the local interactions that mediate enzyme action, and may be an essential factor that allows to achieve high turnover rates as well as exquisite specificity in their reactions. The Program Project is divided into 4 projects, all tightly focused on this long-term goal, and closely tied to each other. Two very different enzyme systems, dihydrofolate reductase (DHFR) and a metallo- beta-lactamase, may have been chosen for intensive study, in the hope that results obtained for the two systems may be generalizable in terms of the guiding hypothesis of the proposal. The first two projects are concerned with experimental measures to determine polypeptide chain dynamics using NMR relaxation and other methods. Project 1 (P.E. Wright, P.I.) will focus on the dynamics using NMR relaxation and other methods. Project 1 (P.E. Wright, P.I.) will focus on the dynamics of DHFR in binary and ternary complexes with substrates, inhibitors and cofactors, and on mutants specifically designed on the basis of preliminary NMR dynamics measurements. A similar protocol will ultimately be followed in Project 2 (H,J. Dyson, P.I.) for the metallo-beta-lactamase. Initial goals for this project will involve resonance assignment and correlation with structure, together with estimates of the dynamics from 15N and 13C relaxation and from amide proton hydrogen exchange rates. Project 3 (S.J. Benkovic, P.I.) will utilize the information provided in Projects 1 and 2 to design site- directed mutants and inhibitors for the two enzymes. This information besides being vital for the enzymes are important drug targets, DHFR for anti-cancer therapy and the metallo-beta-lactamase because it is a major component of antibiotic resistance in pathogenic bacteria. Project 4 (D.A. Case, P.1., C.L. Brooks, III, Co-P.I.) provides the essential theoretical underpinning for the project. Based on information available from Projects 1, 2 and 3, Project 4 will attempt to model reaction pathways consistent with structural, dynamic and kinetic information, providing the potential for a fundamental understanding of reaction mechanisms at an atomic and electronic level. Together, these projects constitute a focused effort to understand enzyme catalysis, incorporating the novel idea that dynamics of the polypeptide may well be an integral and important component of the entire process.