新梨7号多酚氧化酶的纯化及特性分析  

Purification and Characteristics of Polyphenoloxidase from Fruits of Xinli No.7, A Hybrid of Pyrus sinkiangensis and Pyrus bretschneideri Rehd

作　　者：朱永宝[1] 王然[1] 赵玉君[1] 韩希凤[1] 侯召华[1] 代守鑫[1] 杨福臣[1] 王成荣[1] 

机构地区：[1]青岛农业大学食品科学与工程学院,山东青岛266109

出　　处：《食品科学》2009年第17期230-234,共5页Food Science

基　　金："十一五"国家科技支撑计划重点项目(2006BAD22B07);农业部"948"资助项目(2006-G27-7)

摘　　要：对新梨7号多酚氧化酶(PPO)的纯化及部分特性进行研究。结果表明:新梨7号PPO的最适温度和pH值分别为25℃和6.5;经99℃热处理135s和100Hz微波处理15s后,其PPO完全失活;该酶对底物亲和力的大小依次为咖啡酸>绿原酸>儿茶酚;0.5%～3.0%的NaCl、0.05%～0.3%的柠檬酸和EDTA-2Na对新梨7号PPO活性的抑制效果较弱,0.01%～0.1%的VC、L-半胱氨酸、NaHSO3和Na2S2O3对新梨7号PPO活性的抑制效果较好,其中VC的抑制效果最好。Polyphenoloxidase （PPO） was prepared from fruit powder of Xinli No.7 by salt-out precipitation with saturated ammonium sulphate solution followed by purification by DEAE-Sephadex A-50 column chromatography and its enzymological properties were investigated. The optimum working temperature and pH value of Xinli No.7 PPO were 25 ℃ and 6.5 separately. The enzyme was inactivated by both heating treatment for 135 s at 99℃ and microwave treatment for 15 s at 100 Hz. The affinity towards various substrates declined in the following order of caffeic acid 〉 chlorogenic acid 〉 catechol. No obvious inhibition effects of 0.5% -- 3.0% NaCl, 0.01% -- 0.1% citric acid and 0.05% -- 0.3% EDTA-2Na were observed on the PPO activity while VC, L-Cys, NaHSO3 and Na2S203 at the concentration of 0.01%--0.1% all exhibited marked inhibition effects and VC was the most effective inhibitor.

关 键 词：新梨7号 多酚氧化酶 纯化 特性 

分 类 号：Q544.1[生物学—生物化学]