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首页> 外文期刊>Journal of Agricultural and Food Chemistry >Purification and characterization of polyphenol oxidase from garland chrysanthemum (Chrysanthemum coronarium L.)
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Purification and characterization of polyphenol oxidase from garland chrysanthemum (Chrysanthemum coronarium L.)

机译：花环菊花（Chronsanthemum coronarium L.）中多酚氧化酶的纯化和表征

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摘要

Polyphenol oxidase (PPO) of garland chrysanthemum (Chrysanthemum coronarium L.) was purified similar to32-fold with a recovery rate of 16% by ammonium sulfate fractionation, ion exchange chromatography, hydrophobic chromatography, and gel filtration. The purified enzyme appeared as a single band on PAGE and SDS-PAGE. The molecular weight of the enzyme was estimated to be about 47000 and 45000 by gel filtration and SDS-PAGE, respectively. The purified enzyme quickly oxidized chlorogenic acid and (-)-epicatechin. The K-m value (Michaelis constant) of the enzyme was 2.0 mM for chlorogenic acid (pH 4.0, 30 degreesC) and 10.0 mM for (-)-epicatechin (pH 8.0, 40 degreesC). The optimum pH was 4.0 for chlorogenic acid oxiclase (ChO) and 8.0 for (-)-epicatechin oxidase (EpO). In the pH range from 5 to 11, their activities were quite stable at 5 degreesC for 22 h. The optimum temperatures of ChO and EpO activities were 30 and 40 degreesC, respectively. Both activities were stable at up to 50 degreesC after heat treatment for 30 min. The purified enzyme was strongly inhibited by L-ascorbic acid and L-cysteine at 1 mM.
机译：通过硫酸铵分级分离，离子交换色谱，疏水色谱和凝胶过滤，对花环菊花（Chronsanthemum coronarium L.）的多酚氧化酶（PPO）进行了约32倍的纯化，回收率为16％。纯化的酶在PAGE和SDS-PAGE上显示为一条条带。通过凝胶过滤和SDS-PAGE估计该酶的分子量分别为约47000和45000。纯化的酶迅速氧化绿原酸和（-）-表儿茶素。对于绿原酸（pH 4.0，30℃），该酶的K-m值（米高斯常数）为2.0 mM;对于（-）-表儿茶素（pH 8.0，40℃），该酶的K-m值为10.0 mM。绿原酸氧化酶（ChO）的最佳pH值为4.0，（-）-表儿茶素氧化酶（EpO）的最佳pH值为8.0。在5到11的pH范围内，它们的活性在5摄氏度下稳定22小时。 ChO和EpO活性的最佳温度分别为30和40摄氏度。热处理30分钟后，两种活性在最高50℃下都稳定。纯化的酶在1 mM时被L-抗坏血酸和L-半胱氨酸强烈抑制。

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