【摘要】 使用NaCl抽提、硫酸铵分步沉淀、离子交换和疏水柱层析等方法 ,从蕹菜叶绿体类囊体膜中分离纯化到一种蛋白磷酸酯酶 .SDS -PAGE检测表明 ,这种磷酸酯酶的分子量 (Mr)为 14 .9× 10 3 .该酶具有水解磷酸单酯类物质的活性 ,水解pNPP的Km值为 1.76× 10 -6mol/L ;体外测活时最适pH为 5 ,属于酸性磷酸酯酶 ;该酶耐热 ,在 5 0℃时活力达到最高 ,对NaCl不太敏感 ;但EDTA和NaF可以明显影响该酶的活性 .图 6表 3参 2 4更多还原

【Abstract】 A phosphatase was isolated from the chloroplast thylakoid membrane of Ipomoea aquatica by NaCl extration, ammonium sulfate precipitation, ion-exchange chromatography and hydrophic chromatography through Butyl-Toyopearl 650M column. The results from SDS-PAGE showed that the enzyme was a protein with molecular weight ( M r) of 14.9×10 3 . This phosphatase catalyzed hydrolysis of phosphate monoesters pNPP and had a K m of 1.76×10 -6 mol/L. The pH 5 was optimal for the enzyme reaction, indicating it belonged to acid phosphatase, while the optimal temperature of enzyme catalysis was 50 ℃, suggesting it was thermostable. EDTA and NaF inhibited the enzyme activity intensively, however, it was obviously that no effect of NaCl was found on the phosphatase activity. Fig 6, Tab 3, Ref 24更多还原