摘要
经10 KD的膜超滤,DEAE-Sepharose离子交换柱层析,Sephacryl S-200凝胶过滤纯化,从薄荷(MenthahaplocalyxBriq)幼叶中分离纯化出电泳纯的转化酶,该酶提纯倍数为186.3倍,比活力为67.06 U/mg.酶学性质和动力学性质研究表明:该酶不可逆催化蔗糖生成果糖和葡萄糖,最适pH值为5.0,最适温度为55℃,米氏常数Km值为12.25 mmol/L.
Electrophoretically pure invertase was isolated and purified from the young leaves of Mentha haplocalyx Briq by 10 KD membrane ultrafiltration, ion exchange chromatography on DEAE-Sepharose Fast Flow column and gel filtration chromatography on Sephacryl S-200. The preparation was shown to be homogenous on polyacrylamide gel electrophoresis. Its specific activity was 67.06 unit/mg protein and its molecular weight was 130KD. The optimum pH and optimum temperature for the enzyme to catalyze the hydrolysis of sucrose were 5.0 and 55 ℃, respectively. Its Michaelis constant （Km） was determined to be 12.25 mmol/L.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第2期90-94,共5页
Journal of Southwest University(Natural Science Edition)
基金
重庆市科委资助项目(CSTC,2004AC1012)
关键词
薄荷
蔗糖酶
分离纯化
Mentha haplocalyx Briq
invertase
isolation and purification
