PYRUVATE PHOSPHATE DIKINASE

丙酮酸磷酸二激酶

• 批准号: 2391989
• 负责人: DEBRA DUNAWAY-MARIANO
• 金额: $ 5.84万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-01-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2391989
• 关键词: Clostridium; X ray crystallography; active sites; adenosine triphosphate; alcohol phosphotransferase; chemical kinetics; cofactor; computer simulation; conformation; crystallization; divalent metal; electron spin resonance spectroscopy; enzyme mechanism; enzyme substrate analog; enzyme substrate complex; histidine; intermolecular interaction; manganese; metalloenzyme; mutant; nuclear magnetic resonance spectroscopy; phosphoenolpyruvate; pyruvates; site directed mutagenesis

DESCRIPTION (Adapted from the applicant's abstract): This application request funds to continue investigations into the structure and catalytic mechanism of the enzyme pyruvate phosphate dikinase (PPDK). The knowledge gained from these studies will (1) serve as the foundation for the design of drugs to combat human infection by parasites and (2) will provide special insight into the mechanisms and mechanics/dynamics of ligand modulated protein motion. During the next funding period investigators intend to focus on the active site regions of PPDK and specifically, on the structural and electronic changes that occur at these sites during catalytic turnover. This knowledge will expand understanding of catalysis in phosphoryl transfer reactions and, ultimately will serve as the foundation for the design of tight binding inhibitors specific for the PPDK active sites. The specific aims for this phase of the project are to: determine the active site residues which function in metal ion cofactor and substrate binding, in acid/base catalysis and in transition state/intermediate binding and to determine the role of the metal ion cofactors in substrate binding and catalysis. During the next funding period investigators will also examine how domain movement in PPDK provides for the transport of the catalytic histidine between the separate active sites in the enzyme during catalytic turnover. This knowledge will expand our understanding of how catalysis at separate active sites in multienzyme complexes is mediated by an appended carrier ligand (lipoate, pantethiene). The specific aims for this phase of the project are to: define the enzyme conformation assumed during each of the three partial reactions, to deduce the torsional angles altered during the interconversion of the conformers, to pin-point the noncovalent bonding interactions which serve to stabilize the respective conformational states and to measure the rate at which the conformers interconvert and the dependence of the rate on the structural features of the protein.

描述（改编自申请人的摘要）：此申请 要求资金继续调查结构和 丙酮酸磷酸二酮酶（PPDK）的催化机制。 从这些研究中获得的知识将（1）作为基础 用于设计药物以应对寄生虫的人类感染和（2） 将提供有关机制和机制/动力学的特殊见解 配体调制蛋白运动的。 在下一个资金期间，调查人员打算专注于 PPDK的主动部位区域，特别是在结构和 催化周转期间这些位点发生的电子变化。 这些知识将扩大对磷酸催化的理解 转移反应，最终将作为 针对PPDK活性位点特有的紧密结合抑制剂的设计。 该项目此阶段的具体目的是：确定 在金属离子辅因子和底物中起作用的活性位点残基 结合，在酸/碱催化和过渡状态/中间 结合并确定金属离子辅因子在 底物结合和催化。 在下一个资金期间，调查人员还将检查域 PPDK中的运动提供了催化组氨酸的运输 催化过程中酶的单独活性位点之间 周转。 这些知识将扩大我们对催化方式的理解 在多元素复合物中的单独活跃位点，由 附加的载体配体（lipoate，pantethiene）。 具体目标 该项目的阶段是：定义酶构象 在三个部分反应中的每一个中都假定，以推断 在构象异构体的相互转换过程中，扭转角发生了变化， 固定非共价键合的相互作用 稳定相应的构象状态并测量速率 在其中，构象相互互换和速率依赖性 蛋白质的结构特征。