枣尺蠖多酚氧化酶的提取及酶学特性

Extraction and Enzymological Characteristics of Polyphenol Oxidase from Sucra jujube Chu

为了给治理枣尺蠖生物制剂的研发提供一定的理论基础。以枣尺蠖为试验材料,提取其发育过程中起重要作用的多酚氧化酶,并对其酶学特性进行研究。结果表明:枣尺蠖多酚氧化酶用40%饱和度硫酸铵进行盐析效果最好,纯化倍数可达5.8倍。且在酶促反应过程中,底物为10mmol/L的邻苯二酚时,不会发生底物限速行为。多酚氧化酶在pH7.0、37℃时活性最高。多酚氧化酶热稳定性较差,随着保温时间的延长酶活力下降。70℃时将该酶保温9min,酶就趋于完全失活。

For research and development of biological agents, polyphenol oxidase （PPO） was extracted from Sucra jujube Chu and the properties of PPO were studied. The results indicated that, the 5.8-fold purification was achieved when the crude enzyme was treated with 40% saturated （NH4）2SO4. The substrate, 10 mmol/L of eatechol couldn＇ t limit enzymatic reaction speed in the enzyme reaction. The results also reported that, the optimum pH was 7.0 and the best temperature was 37℃ for the tested PPO. At the same time, PPO from Sucra jujube Chu couldn＇t withstand the high temperatures and PPO activity would reduce along with time extension. PPO would be inactive completely after incubation in the temperature of 70℃ for 9 rain.