Paoletti F, Aldinucci D, Mocali A, Caparrini A
Anal Biochem. 1986 May 1;154(2):536-41. doi: 10.1016/0003-2697(86)90026-6.
Superoxide dismutase (EC 1.15.1.1) has been assayed by a spectrophotometric method based on the inhibition of a superoxide-driven NADH oxidation. The assay consists of a purely chemical reaction sequence which involves EDTA, Mn(II), mercaptoethanol, and molecular oxygen, requiring neither auxiliary enzymes nor sophisticated equipment. The method is very flexible and rapid and is applicable with high sensitivity to the determination of both pure and crude superoxide dismutase preparations. The decrease of the rate of NADH oxidation is a function of enzyme concentration, and saturation levels are attainable. Fifty percent inhibition, corresponding to one unit of the enzyme, is produced by approximately 15 ng of pure superoxide dismutase. Experiments on rat liver cytosol have shown the specificity of the method for superoxide dismutase. Moreover, common cellular components do not interfere with the measurement, except for hemoglobin when present at relatively high concentrations. The assay is performed at physiological pH and is unaffected by catalase.
超氧化物歧化酶（EC 1.15.1.1）已通过一种基于抑制超氧化物驱动的NADH氧化的分光光度法进行了测定。该测定由一个纯化学反应序列组成，涉及EDTA、Mn(II)、巯基乙醇和分子氧，既不需要辅助酶也不需要复杂的设备。该方法非常灵活且快速，适用于高灵敏度地测定纯超氧化物歧化酶制剂和粗制超氧化物歧化酶制剂。NADH氧化速率的降低是酶浓度的函数，并且可以达到饱和水平。大约15 ng的纯超氧化物歧化酶可产生50%的抑制，相当于一个酶单位。对大鼠肝细胞溶胶的实验表明了该方法对超氧化物歧化酶的特异性。此外，除了血红蛋白在相对高浓度存在时外，常见的细胞成分不会干扰测量。该测定在生理pH下进行，不受过氧化氢酶的影响。
