Studies on the Mechanism and Control of Enzyme Action

酶作用机制及控制研究

• 批准号: 9603595
• 负责人: Herbert Fromm
• 金额: $ 25.35万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9603595&HistoricalAwards=false
• 关键词: Studies; Mechanism; Control; Enzyme; Action

9603595 Fromm The structure of Adenylosuccinate synthetase from E. coli, the first committed step in the conversion of IMP to AMP in the de novo purine nucleotide biosynthetic pathway, as the unligated enzyme and complexed, with a variety of substrates and substrate analogs, is now available. During the proposed grant period the PI will prepare and study the properties of mutant forms of AMPSase, based on the crystal structure, in an attempt to gain insight into the enzyme's catalytic and regulatory mechanisms at the molecular level. Those mutant forms of AMPSase that appear to be of interest will be crystallized where possible and subjected to structural analysis. The mode of AMPSase regulation is not known; however, the state of subunit association may play a role in the regulation of AMPSase activity and this possibility will be investigated using both kinetic and physical techniques. It was found that mixing of two different inactive mutant forms of AMPSase can lead to the formation of active heterodimers. The physical basis behind this finding will be investigated. *** AMPSase synthetase is an enzyme that plays a crucial role in all living organisms. It catalyzes the first committed step in the biosynthesis of purine nucleic acids, which go on to form DNA and RNA, along with other cellular nucleotides of importance in regulation of metabolism. Understanding how this enzyme functions can also have potential for the design of chemotherapeutic agents. ***

9603595从来自大肠杆菌的腺基琥珀酸合成酶的结构中，作为未连接的酶和与各种底物和底物类似物的络合物，现在已经可以使用在从头合成嘌呤核苷酸的途径中将IMP转化为AMP的第一步。在拟议的授权期内，PI将根据晶体结构制备和研究AMPSase突变形式的性质，试图在分子水平上深入了解酶的催化和调节机制。那些看起来有意义的AMPSase突变形式将在可能的情况下结晶并进行结构分析。AMPSase的调节方式尚不清楚，但亚基结合状态可能在AMPSase活性的调节中发挥作用，这种可能性将使用动力学和物理技术进行研究。研究发现，AMPSase两种不同失活突变形式的混合可导致活性异二聚体的形成。这一发现背后的物理基础将得到调查。*AMPSase合成酶是一种在所有生物中发挥关键作用的酶。它催化嘌呤核酸生物合成的第一步，然后与其他在新陈代谢调节中重要的细胞核苷酸一起形成DNA和RNA。了解这种酶的功能也可能有助于化疗药物的设计。***