Studies on the Mechanism and Control of Enzyme Action

酶作用机制及控制研究

• 批准号: 9218763
• 负责人: Herbert Fromm
• 金额: $ 22.2万
• 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: 1993
• 资助国家: 美国
• 起止时间: 1993-03-15 至 1997-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218763&HistoricalAwards=false
• 关键词: Studies; Mechanism; Control; Enzyme; Action

The enzyme adenylosuccinate synthetase obtained from E. coli is dimeric and binds three substrates plus a metal ion. The chemical mechanism of the function of the synthetase is approached from a number of points of view. Specific amino acid residues involved in binding and catalytic processes are examined via chemical and metagenesis approaches. These studies require considerable spectroscopic effort to localize the observed effects. Chemical and spectroscopic exchange studies will be performed to get at central questions of the timing and order of binding and catalytic steps. Ongoing crystallograpic studies of wild type and mutant enzyme as well as enzyme in the presence of inhibitors will be continued. %%% Adenylosuccinate synthetase is involved in the conversion of AMP from IMP. By virtue of its location at the beginning of a metabolic pathway, this enzyme is subject to a number of controls of its catalytic activity as part of the overall metabolic integration of the cell. The proposed research explores the complex interactions which exist between the enzyme and metabolites and inhibitors it binds. The proposed research will identify the order and tightness of binding of effectors, substrates, and products, will identify catalytically important structures in the enzyme, and will identify and characterize intermediates occurring along the reaction pathway. Studies of the three-dimensional structure of the enzyme, using X-ray crystallography, will be continued.

从大肠杆菌中获得的腺苷酸琥珀酸合成酶是二聚体，可结合三种底物和一个金属离子。 从多个角度探讨合成酶功能的化学机制。 通过化学和元发生方法检查参与结合和催化过程的特定氨基酸残基。 这些研究需要大量的光谱工作来定位观察到的效应。 将进行化学和光谱交换研究，以了解结合和催化步骤的时间和顺序的核心问题。 将继续对野生型和突变型酶以及抑制剂存在下的酶进行晶体学研究。 %%% 腺苷酸琥珀酸合成酶参与从 IMP 到 AMP 的转化。 由于其位于代谢途径起点的位置，作为细胞整体代谢整合的一部分，该酶的催化活性受到多种控制。 拟议的研究探讨了酶与其结合的代谢物和抑制剂之间存在的复杂相互作用。 拟议的研究将确定效应子、底物和产物结合的顺序和紧密程度，确定酶中具有催化作用的重要结构，并确定和表征沿反应途径发生的中间体。 将继续利用 X 射线晶体学研究酶的三维结构。