Sawada H, Hara A, Nakayama T, Hayashibara M
J Biochem. 1982 Jul;92(1):185-91. doi: 10.1093/oxfordjournals.jbchem.a133915.
The kinetic properties of the NADPH-dependent reduction of aromatic aldehydes and ketones catalyzed by low- and high-molecular-weight aldehyde reductases [alcohol : NADP oxidoreductase, EC 1.1.1.2] and 3 alpha- and 3 beta-hydroxysteroid dehydrogenases [EC 1.1.1.50 and 1.1.1.51] of rabbit liver were compared. Initial velocity measurements with pyridine-4-aldehyde, 4-benzoylpyridine and androstadione as substrates and inhibition studies with their products indicated that all the enzymes followed an ordered Bi Bi reaction mechanism with coenzyme binding first and leaving last. However, phenylpyruvic acid inhibited 3 alpha-hydroxysteroid dehydrogenase and low-molecular-weight aldehyde reductase noncompetitively with respect to either NADPH or substrate, whereas it inhibited 3 beta-hydroxysteroid dehydrogenase and high-molecular-weight aldehyde reductase uncompetitively. Cibacron blue F3GA dye was a dead-end inhibitor of the enzymes, being competitive with respect to NADPH and noncompetitive with respect to the other substrate, but the Ki value of 3 alpha-hydroxysteroid dehydrogenase for this dye was much higher than those of the other enzymes.
比较了兔肝中低分子量和高分子量醛还原酶[醇：NADP氧化还原酶，EC 1.1.1.2]以及3α-和3β-羟基类固醇脱氢酶[EC 1.1.1.50和1.1.1.51]催化的NADPH依赖性还原芳香醛和酮的动力学特性。以吡啶-4-醛、4-苯甲酰吡啶和雄甾二酮为底物进行的初始速度测量以及对其产物的抑制研究表明，所有这些酶都遵循有序的双底物双产物反应机制，辅酶首先结合且最后离开。然而，苯丙酮酸对3α-羟基类固醇脱氢酶和低分子量醛还原酶的抑制作用相对于NADPH或底物而言是非竞争性的，而对3β-羟基类固醇脱氢酶和高分子量醛还原酶的抑制作用则是反竞争性的。汽巴克隆蓝F3GA染料是这些酶的一种终产物抑制剂，对NADPH具有竞争性，对另一种底物具有非竞争性，但3α-羟基类固醇脱氢酶对该染料的Ki值远高于其他酶。
