Effect of Calcium Cation on Thermophilic Acylamino Acid-releasing Enzyme Ape1547 from Aeropyrum pernix K1  

作　　者：ZHOU Jun XIE Gui-qiu CAO Shu-gui GAO Ren-jun 

机构地区：[1]Key Laboratory for Molecular Enzymology and Engineering, Ministry of Education [2]School of Pharmaceutical Sciences, Jilin University, Changchun 130021, P. R. China

出　　处：《Chemical Research in Chinese Universities》2009年第4期513-517,共5页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Nos.30400081 and 20772046)

摘　　要：The gene of enzyme（Ape1547） was cloned from hyperthermophilic archaeon Aeropyrum pernix K1 and expressed in Escherichia coil.The effect of calcium cation on the properties of Ape1547 was studied.Ape1547 exhibits both peptidase activity and esterase activity.The fluorescence spectrum shows that calcium cation quenches the fluorescence of the enzyme through static quenching mechanism,indicating that calcium cation was bound to the enzyme.Based on the study of calcium cation on CD ellipticity of Ape1547 by circular dichroism,we concluded that the change of enzyme structure induced by calcium cation may be responsible for the change of enzyme activity.Calcium cation has dual effects on Ape1547：it could activate the enzyme activity when its concentration was 0.1 mol/L,and the enzyme had the highest activity;however,when its concentration was higher than 0.2 mol/L,the enzyme activity was inhibited.The results indicate that the activity center of peptidase activity might involve more amino acid residues than that of esterase activity.The gene of enzyme（Ape1547） was cloned from hyperthermophilic archaeon Aeropyrum pernix K1 and expressed in Escherichia coil.The effect of calcium cation on the properties of Ape1547 was studied.Ape1547 exhibits both peptidase activity and esterase activity.The fluorescence spectrum shows that calcium cation quenches the fluorescence of the enzyme through static quenching mechanism,indicating that calcium cation was bound to the enzyme.Based on the study of calcium cation on CD ellipticity of Ape1547 by circular dichroism,we concluded that the change of enzyme structure induced by calcium cation may be responsible for the change of enzyme activity.Calcium cation has dual effects on Ape1547：it could activate the enzyme activity when its concentration was 0.1 mol/L,and the enzyme had the highest activity;however,when its concentration was higher than 0.2 mol/L,the enzyme activity was inhibited.The results indicate that the activity center of peptidase activity might involve more amino acid residues than that of esterase activity.

关 键 词：Acylamino acid-releasing enzyme Aeropyrum pernix K1 Conformational change Calcium cation 

分 类 号：O636.1[理学—高分子化学] S435.622.3[理学—化学]