argE基因在大肠杆菌中的表达优化

N-乙酰鸟氨酸脱酰基酶可在重组菌BL21（DE3）-pET22b-argE中表达。首先确定了该酶的细胞表达定位，再研究了诱导温度、诱导剂种类及浓度、诱导起始菌体密度、诱导时间等因素对重组菌生长及目的蛋白表达活性的影响。结果表明，IPTG和乳糖皆可诱导目的蛋白表达，乳糖的诱导效果优于IPTG。在诱导起始0D600为0．46时加入15g／L乳糖，20℃诱导18h最适于目的蛋白的活性表达。表达条件优化后，酶活从1．68U／mL提高至282．99U／mL，约为原来的168倍。

Optimization of the expression of arg E gene in E.coli

N-acetylornithine deacetylase was expressed in recombinant bacteria BL21 （DE3）-pET22b- argE. The location of the target protein was determined. The effects of induction temperature, type of in- ducer concentration of inducer, initial cell density, induction time on the activity expression of the target protein were studied. The results showed that both IPTG and lactose could be inducers, and the induction effect of lactose was better than that of IPTG. With the optimized active inducing condition of adding 15 g/L lactose at initiated OD600 of 0. 46 and cultivating for 18h at 20℃, the NAOase activity was in- creased by 168 folds from initial 1.68U/mL to 182.99U/mL.