Bolann B J, Ulvik R J
Laboratory of Clinical Biochemistry, University of Bergen, Haukeland Hospital, Norway.
Clin Chem. 1991 Nov;37(11):1993-9.
The growing interest in measuring superoxide dismutase (EC 1.15.1.1) in many diseases calls for useful routine assays. For this purpose, the direct spectrophotometric method of Marklund (J Biol Chem 1976;251:7504-7) was improved to offer an alternative to the imprecise, indirect assays currently used. The decay of O2.- (from KO2) at pH 9.5 was monitored as the decrease in delta A (delta A = A250nm-A360nm). Superoxide dismutase was determined from the pseudo-first-order rate constant of O2.- dismutation. The precision of the assay was improved by increasing the concentration of O2.- and expanding the interval for measurements of O2.- concentrations to 4-16 mumol/L. Other assay characteristics, including temperature, were also optimized. In hemolysate the assay had a within-day CV of 5.5-13% and a between-day CV of 4%. Mn-superoxide dismutase and some superoxide dismutase mimics are inhibited at alkaline pH. Therefore, the method is primarily recommended for Cu,Zn-superoxide dismutase.
在许多疾病中，对超氧化物歧化酶（EC 1.15.1.1）进行检测的兴趣日益增长，这就需要实用的常规检测方法。为此，对马尔克伦德的直接分光光度法（《生物化学杂志》1976年；251:7504 - 7）进行了改进，以替代目前使用的不精确间接检测方法。在pH 9.5条件下监测O₂⁻（来自KO₂）的衰减，以ΔA（ΔA = A₂₅₀nm - A₃₆₀nm）的降低来表示。超氧化物歧化酶是根据O₂⁻歧化的准一级速率常数来测定的。通过提高O₂⁻的浓度并将O₂⁻浓度的测量区间扩大到4 - 16 μmol/L，提高了检测的精密度。还对包括温度在内的其他检测特性进行了优化。在溶血产物中，该检测方法的日内变异系数为5.5 - 13%，日间变异系数为4%。锰超氧化物歧化酶和一些超氧化物歧化酶模拟物在碱性pH条件下会受到抑制。因此，该方法主要推荐用于铜锌超氧化物歧化酶的检测。
