Mg^(2+)、Co^(2+)、Mn^(2+)和Ca^(2+)对葡萄糖异构酶活性的影响  

Effects of Metal Ions Mg^(2+) 、Co^(2+) 、Mn^(2+) and Ca^(2+) on the Activity of Glucose Isomerase

作　　者：陶丽梅[1] 过莹立 李宁 王淳[1] 滕脉坤[1] 王玉珍[1] 

机构地区：[1]中国科学技术大学生命科学学院,合肥230027

出　　处：《中国生物化学与分子生物学报》1999年第6期1002-1005,共4页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家"八六三"资助

摘　　要：The glucose isomerase(GI) was a metal activating enzyme It was most activated by Co 2+ and Mg 2+ ,and Mg 2+ was the best activator,whether the glucose or the xylose was the substrate When the glucose was substrate,the dissociation constant of Mg 2+ GI,Co 2+ GI and Mn 2+ -GI was 115 μmol/L,40 μmol/L, and 15 μmol/L respectively. The maximum activity of Mg 2+ GI,Co 2- GI and Mn 2+ GI was 100%,85%,and 20% respectively. When the xylose was substrate,the order of dissociation constant and maximum activity of the metal enzymes was the same Ca 2+ was a competitive inhibitor versus Mg 2+ ( K i 7 4 μmol/L)or Co 2+ ( K i 99 μmol/L). Compared with Mg 2+ GI,the K m of Co 2+ GI was more,and the V M of Co 2+ GI less The process of activity recovery from apo GI to metal GI showed that it was slow and of twoThe glucose isomerase(GI) was a metal activating enzyme It was most activated by Co 2+ and Mg 2+ ,and Mg 2+ was the best activator,whether the glucose or the xylose was the substrate When the glucose was substrate,the dissociation constant of Mg 2+ GI,Co 2+ GI and Mn 2+ -GI was 115 μmol/L,40 μmol/L, and 15 μmol/L respectively. The maximum activity of Mg 2+ GI,Co 2- GI and Mn 2+ GI was 100%,85%,and 20% respectively. When the xylose was substrate,the order of dissociation constant and maximum activity of the metal enzymes was the same Ca 2+ was a competitive inhibitor versus Mg 2+ ( K i 7 4 μmol/L)or Co 2+ ( K i 99 μmol/L). Compared with Mg 2+ GI,the K m of Co 2+ GI was more,and the V M of Co 2+ GI less The process of activity recovery from apo GI to metal GI showed that it was slow and of two steps

关 键 词：葡萄糖异构酶 酶活性 MG^2+ CO^2+ MN^2+ CA^2+ 

分 类 号：Q558[生物学—生物化学]