摘要
多酚氧化酶(PPO)是一种含多个铜离子的氧化还原酶,可催化酚类物质氧化为醒类物质。我们从八棱海棠中克隆到一个PPO的同源基因MdPPO2B,构建该基因酵母分泌表达载体并转化到毕赤酵母GS115中。SDS-PAGE电泳结果显示,表达蛋白MdPP02B的分子量约为66.4 kDa。以邻苯二酚作为底物,该酶的最适pH和温度分别为6.5和40℃。除Cu^(2+)、Na^+、Mg^(2+)和Li^+外,4 mmol·L^(-1)的Fe^(3+),Zn^(2+),Mn^(2+)对酶活力表现出较强的抑制作用。在最适条件下,当苯酚浓度达600μmol·L^(-1)时,反应4h,MdPPO2B表达菌株可降解80%的苯酚。表明该基因在工业污水处理中具有广阔的应用潜力。
Polyphenol oxidase(PPO) is one of oxidoreductase enzymes,which catalyzes the phenols to diquinones.A putative PPO gene(MdPP02B) was cloned from Malus robusta and exogenously expressed in Pichia pastoris GS115.SDS-PAGE showed that MdPP02 B has a molecular mass of approximately 66.4 kDa.With catechol as substrate,it was showed that the optimum pH and temperature for MdPP02 B was 6.5 and 40 °C,respectively.Except for Cu^(2+),Na~+,Mg^(2+) and Li~+,Fe^(3+),Zn^(2+) and Mn^(2+) inhibited the enzyme activity at a concentration of 4 mmol·L^(-1).The MdPPO2 B degraded 80%phenol after incubated for 4 h under the optimum condition.In short,our original research on MdPPO2 B may provide reference for the application of microorganism in industrial wastewater.
出处
《植物生理学报》
CAS
CSCD
北大核心
2015年第12期2239-2246,共8页
Plant Physiology Journal
基金
上海市种业发展项目[沪农科种字(2013)第13号]
上海市科学技术委员会科研计划项目(13395800300)
关键词
多酚氧化酶
八棱海棠
酶学性质
苯酚降解
polyphenol oxidase
Malus robusta
enzymatic characteristics
phenol degradation