【摘要】 谷氨酰胺转氨酶（transglutaminase, TGase）可以促进蛋白质分子内或分子间的交联，在食品、制药、纺织等行业中均有着广泛的应用。为了高效生产具有优良特性的TGase,该研究以茂源链霉菌（Streptomyces mobaraensis）来源的TGase为研究对象，比较了两个不同来源的TGase的性质，将具有较优酶学性质的TGase基因tg_LD分别采用6种不同质粒在大肠杆菌（Escherichia coli）中进行异源表达。其中，重组菌E.coli BL21（DE3）(pET32a-tg_LD)实现了成熟TGase的异源表达，添加0.2 mmol/L IPTG、25℃诱导8 h,重组TG_LD的酶活力为0.45 U/mL。为进一步提高TG_LD的表达量，构建了可以特异性激活pro-TGase的2种表达载体。其中，重组菌E.coli BL21（DE3）(pCOLDⅡ-pro-EK-tg_LD),添加0.2 mmol/L IPTG、15℃诱导24 h,体外活化后获得具有活性的TG_LD酶，其酶活力达25.23 U/mL。该研究实现了具有优良性质的活性TG_LD在E.coli中的高效表达。更多还原

【Abstract】 Transglutaminase（TGase） can promote intramolecular or intermolecular cross-linking of proteins, and is widely used in food, pharmaceutical, textile, and other industries.In order to efficiently produce TGase with excellent properties, two TGases from Streptomyces mobaraensis were investigated in this study.The properties of two TGases from different strains were investigated, and the TGase gene tg_LD with excellent properties was heterologously expressed in Escherichia coli using six different plasmids, respectively.Mature TGase was successfully expressed in the recombinant E.coli BL21（DE3）(pET32a-tg_LD).The activity of recombinant TG_LD reached 0.45 U/mL after 8 h induction using 0.2 mmol/L IPTG at 25 ℃.In order to further improve the expression level of TG_LD, two recombinant strains were constructed to specifically activate pro-TGase, respectively.The activity of TG_LD in recombinant E.coli BL21（DE3）(pCOLDII-pro-EK-tg_LD) after activation in vitro reached 25.23 U/mL after 24 h induction using 0.2 mmol/L IPTG at 15 ℃.Activated TG_LDwith excellent properties were efficiently expressed in E.coli in this study.更多还原