【摘要】 来源于地衣芽孢杆菌的漆酶具有催效率高,底物范围广等优点在工农业等领域具有重要的应用前景,但该酶在外源基因表达系统中的表达量低,影响了其在工农业等领域的应用。His-tag和S-tag两种标签由于具有分子量小,且一般不影响外源蛋白性质等特点,在外源蛋白的纯化和检测中具有重要的应用。本研究发现将来源于地衣芽孢杆菌的漆酶Cot A的N端融合Histag或S-tag构建于p ET-22b载体,并转化大肠杆菌BL21(DE3)后可以显著提高其在大肠杆菌中的可溶性表达量,其表达量较N端无融合标签的构建,His-tag可提高漆酶表达量约为37倍,S-tag约可提高20倍,His-tag与S-tag共作用约可提高28倍。更多还原

【Abstract】 Laccase from Bacillus licheniformis has the advantages of high catalytic efficiency,wide range of substrates,etc.,thus it owns the broad application prospect in industrial and agricultural fields. However,the e xpression level of the enzyme in the foreign gene expression system is low,which greatly limits its application in the agricultural and industrial fields. His-tag or S-tag is the small peptide with low molecular weight and usually can not affect the characteristics of heterologous fusion protein,and they are beneficial to be applied in the purification and detection of heterologous proteins. In this study,fusion of His-tag and/or S-tag on the N-terminal of the laccase Cot A from B. licheniformis was constructed into p ET-22 b vector,and the vector was transferred into Escherichia coli BL(DE3),then we found that the soluble expression level of laccase significantly increased in E. coli BL(DE3). Compared with the construction without no fusion of any tags on N-terminal,the expression level with His-tag was about 37 folds,20 folds with S-tag,and 28 folds with both His-tag and S-tag,respectively.更多还原