Sidhu R S, Blair A H
J Biol Chem. 1975 Oct 10;250(19):7899-904.
Steady state initial velocity studies were carried out to determine the kinetic mechanism of human liver aldehyde dehydrogenase. Intersecting double reciprocal plots obtained in the absence of inhibitors demonstrated that the dehydrogenase reaction proceeded by sequential addition of both substrates prior to release of products. Dead end inhibition patterns obtained with coenzyme and substrate analogues (e.g. thionicotinamide-AD+ and chloral hydrate) indicated that NAD+ and aldehyde can bind in random fashion. The patterns of inhibition by the product NADH and of substrate inhibition by glyceraldehyde were also consistent with this mechanism. However, comparisons between kinetic constants associated with the dehydrogenase and esterase activities of this enzyme suggested that most of the dehydrogenase reaction flux proceeds via formation of an initial binary NAD+-enzyme complex over a wide range of substrate and coenzyme concentrations.
进行稳态初始速度研究以确定人肝脏醛脱氢酶的动力学机制。在不存在抑制剂的情况下获得的相交双倒数图表明，脱氢酶反应在产物释放之前通过依次添加两种底物进行。用辅酶和底物类似物（如硫代烟酰胺 - AD + 和水合氯醛）获得的终产物抑制模式表明，NAD + 和醛可以随机方式结合。产物NADH的抑制模式和甘油醛的底物抑制模式也与该机制一致。然而，该酶的脱氢酶和酯酶活性相关动力学常数之间的比较表明，在广泛的底物和辅酶浓度范围内，大多数脱氢酶反应通量通过形成初始二元NAD + -酶复合物进行。
