Characterization and cloning and expression of Polyphenol Oxidase (PPO) from Canarium album

多酚氧化酶（EC.1.14.18.1）广泛存在于动物、植物和微生物体内，是一种由核基因编码的含铜金属酶。它是果蔬储藏和加工过程中酶促褐变的重要酶类，能够催化酚类物质的氧化。以橄榄（长营）为原料提取多酚氧化酶进行了分离纯化，得到比活力为1834U/mg的多酚氧化酶粗酶液。研究橄榄多酚氧化酶的理化性质，酶的pH和最适温度分别为6.0和30℃，酶在低于60℃和在pH4.0~8.0范围内较稳定；在30℃、pH6.0条件下，多酚氧化酶催化L-DOPA氧化反应的Km为3.884mmol/L。测定了几种修饰剂对橄榄多酚氧化酶的修饰作用，结果表明二硫键、精氨酸残基、赖氨酸残基和丝氨酸残基对多酚氧化酶具有修饰作...Polyphenol oxidase is widely distributed in animals, plants and microorganisms. It’s a copper-containing enzyme which has complex constructures. Polyphenol oxidase play an important role during the process of enzymetic browning in vegetable and fruit, for the reason that it can catalyze the melanin synthesis. In this paper, we purified the PPO from Canarium album and studied so...学位：理学硕士院系专业：生命科学学院_细胞生物学学号：2162013115254