摘要
通过热变性、硫酸铵沉淀、DEAE-Sephadex-A50阴离子交换层析和CM Sepharose Fast Flow阳离子交换层析等一系列步骤从有机磷农药降解菌Plesiomonas sp.M6中获得了甲基对硫磷水解酶（Methyl parathion hydrolase，MPH，EC3．1．8．3）的电泳纯。酶谱显示和SDS-PAGE电泳表明纯化的酶只有一条条带，其分子量约为33kD。该酶热稳定性比较高，55℃、15min处理后酶活保持稳定，最适反应pH为9．0，景适反应温度在10℃左右。动力学分析表明其对甲基对硫磷的米氏常数（Km）为2．14mmol／L，最大反应速度（Vmax）为14．08μmol／L．min，转换数（kcat）为2863s^-1。
A novel methyl parathion hydrolase from Plesiomonas sp. M6 was purified to homogeneity by heat denaturation, ammonium sulfate precipitation, DEAE-Sephadex-A50 ion exchange chromatography and CM Sepharose Fast Flow cation exchange chromatography. The dynamics and enzymatic properties of the purified MPH were studied. Treated at 55℃ for 15 minutes, the activity of MPH almost remained the same as before. The optimal catalytic pH and T were 9.0 and 10℃, respectively. The molecular mass of MPH was around 33kD measured by SDS-PAGE. With methyl parathion as the substrate, the Km was 2.14mmol/1. the Vmax was 14.08μmol/1.min and the kcat was 2863s^-1
出处
《高技术通讯》
CAS
CSCD
北大核心
2006年第1期84-87,共4页
Chinese High Technology Letters
基金
863计划（2004AA246070）和国家自然科学基金（30300005）资助项目.
关键词
甲基对硫磷水解酶(MPH)
邻单胞菌M6
纯化
性质
methyl parathion hydrolase （MPH）, Plesiomonas sp. M6, purification, characterization
