Van Lente F, Pepoy M
Department of Biochemistry, Cleveland Clinic Foundation, OH 44195.
Clin Chem. 1990 Jul;36(7):1339-43.
This coupled-enzyme method for determining the activity of catalase (EC 1.11.1.6) in erythrocyte lysates is based on measuring the absorbance at 340 nm of NADH produced from the peroxidic reaction between ethanol, hydrogen peroxide, and catalase. Hydrogen peroxide is produced as a substrate in situ from the oxidation of glucose catalyzed by glucose oxidase (EC 1.1.3.4). Catalase oxidizes ethanol to acetaldehyde in the presence of hydrogen peroxide. Acetaldehyde is then oxidized by aldehyde dehydrogenase (EC 1.2.1.5) to produce acetate with concomitant conversion of NAD+ to NADH. The reaction did not follow strict zero-order kinetics; enzyme activity was quantified by using initial rates and standards prepared from purified catalase. The method demonstrated within-run and between-run CVs of 1.0% to 2.9% and 2.4% to 3.3%, respectively. This semiautomated method correlated well (r = 0.92) with the more tedious manual method involving measurement at 240 nm.
这种用于测定红细胞裂解物中过氧化氢酶（EC 1.11.1.6）活性的偶联酶法，是基于测量乙醇、过氧化氢和过氧化氢酶之间过氧化物反应产生的NADH在340nm处的吸光度。过氧化氢是由葡萄糖氧化酶（EC 1.1.3.4）催化葡萄糖氧化原位产生的底物。过氧化氢酶在过氧化氢存在下将乙醇氧化为乙醛。然后乙醛被醛脱氢酶（EC 1.2.1.5）氧化生成乙酸，同时NAD+转化为NADH。该反应不遵循严格的零级动力学；通过使用初始速率和由纯化的过氧化氢酶制备的标准品来定量酶活性。该方法的批内和批间CV分别为1.0%至2.9%和2.4%至3.3%。这种半自动方法与涉及在240nm处测量的更繁琐的手动方法相关性良好（r = 0.92）。
