Oppenheimer N J
J Biol Chem. 1986 Sep 15;261(26):12209-12.
The stereospecificity of the enzyme-dependent oxidation of alpha-[4R-2H]NADH has been determined for four dehydrogenases: two pro-R specific enzymes, pig heart malate dehydrogenase and yeast alcohol dehydrogenase; and two pro-S specific enzymes, rabbit muscle glycerol-3-phosphate dehydrogenase and Rhodopseudomonas spheroides 3-hydroxybutyrate dehydrogenase. In all cases, an enzyme-dependent and substrate-specific oxidation to alpha-NAD+ is observed with the stereochemistry of oxidation identical with that found for the oxidation of the correspondingly labeled beta-NADH. The ability of dehydrogenases from diverse sources to utilize alpha-NADH in a stereochemically competent fashion is discussed in relation to proposed interactions between the nicotinamide sugar moiety and active site residues or obligatory alignments of the pyridine and sugar moieties.
已针对四种脱氢酶测定了依赖酶的α-[4R-2H]NADH氧化反应的立体特异性：两种对前-R具有特异性的酶，即猪心苹果酸脱氢酶和酵母乙醇脱氢酶；以及两种对前-S具有特异性的酶，即兔肌甘油-3-磷酸脱氢酶和球形红假单胞菌3-羟基丁酸脱氢酶。在所有情况下，均观察到依赖酶且底物特异性的氧化生成α-NAD+，其氧化的立体化学与相应标记的β-NADH氧化时所发现的相同。结合烟酰胺糖部分与活性位点残基之间的拟相互作用或吡啶和糖部分的必需排列，讨论了来自不同来源的脱氢酶以立体化学上合适的方式利用α-NADH的能力。
