以邻苯二酚为底物,采用分光光度法对白玉菇PPO的酶学特性进行了研究。结果表明,样品PPO酶促反应产物的最大吸收波长为420 nm,反应时长应为3 min;反应的最适pH值为6.5,最适温度为35℃,最适底物浓度为0.10 mol/L;白玉菇PPO酶促反应的动力学方程为1/V=2.752264/[S]+17.348 9,米氏常数为:Km=0.159mol/L,白玉菇菌柄多酚氧化酶活性高于菌盖。

The characteristics of polyphenol oxidase(PPO) in white Hypsizygus marmoreus were studied by spectrophotometer using catechol as the substrate.The results indicated that the absorptive wavelength of enzymatic reactive product was 420nm,and the reaction lasted for at least 3min,while the optimal conditions for PPO were 35℃ and pH 6.5,and the optimal substrate concentration was 0.10 mol/L.The kinetic equation of PPO was 1/V=2.752 264/[S] +17.348 9,and its Km was 0.159 mol/L.The PPO activity of stipe was much higher than other parts.