蟹味菇多酚氧化酶的特性研究

Properties of Polyphenol Oxidase Extracted from Crab Mushroom

采用0.2mol/L磷酸盐缓冲溶液匀浆法从蟹味菇中提取多酚氧化酶(PPO),并对该多酚氧化酶的酶学特性进行了研究。试验结果表明,以邻苯二酚为底物,该酶的最适pH6.4,最适温度为35℃,Km值为0.0875mol/L,Vmax值为0.0375U/min,70℃热处理12.5min或75℃热处理10min可完全钝化PPO的活性,10mmol/L的EDTA和柠檬酸亚锡二钠均能有效抑制PPO的酶活性。

The polyphenol oxidase（PPO） of crab mushroom was extracted by 0.2 mol/L phosphate buffer and its properties was analysed.Experimental results showed that the optimal pH and temperature were 6.4 and 35 ℃ respectively,and the Km value and Vmax value with catechol substrate were 0.0875 mol/L and 0.0375 U/min respectively,and the PPO would be inactive in 12.5 min when the water tempreture was 70 ℃ or in 10 min when the water tempreture was 75 ℃.EDTA and disodium stannous citrate were strong inhibitors,the effective concentrations of the two kinds of inhibitors were 10mmol/L respectively.