KINETIC AND CHEMICAL MECHANISM OF ENZYMES

酶的动力学和化学机制

• 批准号: 3071147
• 负责人: PAUL F COOK
• 金额: $ 4.99万
• 依托单位: TEXAS COLLEGE OF OSTEOPATHIC MEDICINE
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-04-01 至 1988-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3071147
• 关键词: 6 phosphofructokinase; acidity /alkalinity; aspartate transaminase; chemical kinetics; chemical structure; enzyme model; enzyme structure; enzyme substrate; glutamate dehydrogenase; high performance liquid chromatography; malate dehydrogenase; nonradiation isotope effect; stable isotope; stoichiometry; ultraviolet spectrometry

The kinetic mechanism of an enzyme is determined in two parts: the order of addition of substrates and release of products and the location of slow steps along the reaction pathway. Techniques are available to obtain this information which include initial rate studies in the presence and absence of products and dead end inhibitors, isotope exchange at equilibrium, and isotope effect studies. More recent advances in steady state kinetic theory have shown that the chemical catalytic mechanism can also be obtained using a determination of the pH variation of primary and secondary isotope effects (particularly secondary effects which are more sensitive to transition state structure) and kinetic parameters (for example, Vmax, V/K, and Ki for a substrate or inhibitor). It is the goal of this project to determine the mechanism of action of enzymes which include malic enzyme from Ascaris suum (responsible for the oxidative decarboxylation of L-malate by DPN to pyruvate and CO2) using the approach outlined above. This kind of approach has been used with success for several enzymes including hexokinase and fructokinase but only a very small number of enzymes have mechanisms which are known with any degree of certainty.

酶的动力学机制分为两个部分： 添加底物和产品的释放以及慢速的位置 沿着反应途径的步骤。 可以获得此功能 信息包括在存在和不存在的情况下进行初始速率研究 产品和死胡同抑制剂，平衡处的同位素交换以及 同位素效应研究。 稳态动力学的最新进展 理论表明，化学催化机制也可以是 使用原发性和次级的pH变化确定 同位素效应（尤其是对次要效应，对 过渡状态结构）和动力学参数（例如，vmax，v/k， 和基板或抑制剂的Ki）。 这个项目的目标是 确定酶的作用机理，包括苹果酶 来自ascaris suum（负责氧化脱羧 通过DPN到丙酮酸和CO2）使用上面概述的方法。 这种方法已成功用于多种酶 包括己糖激酶和果糖酶，但只有很少的数量 酶具有具有任何确定性的机制。