Ushasree Mrudula Vasudevan, Vidya Jalaja, Pandey Ashok
Biotechnol Lett. 2014 Jan;36(1):85-91. doi: 10.1007/s10529-013-1322-3.
A phytase gene from Aspergillus niger was isolated and two Escherichia coli expression systems, based on T7 RNA polymerase promoter and tac promoter, were used for its recombinant expression. Co-expression of molecular chaperone, GroES/EL, aided functional cytosolic expression of the phytase in E. coli BL21 (DE3). Untagged and maltose-binding protein-tagged recombinant phytase showed an activity band of ~49 and 92 kDa, respectively, on a zymogram. Heterologously-expressed phytase was fractionated from endogenous E. coli phytase by (NH4)2SO4 precipitation. The enzyme had optimum activity at 50 °C and pH 6.5.
从黑曲霉中分离出一种植酸酶基因，并使用基于T7 RNA聚合酶启动子和tac启动子的两种大肠杆菌表达系统进行其重组表达。分子伴侣GroES/EL的共表达有助于植酸酶在大肠杆菌BL21(DE3)中进行功能性胞质表达。未标记和麦芽糖结合蛋白标记的重组植酸酶在酶谱上分别显示出~49 kDa和92 kDa的活性条带。通过硫酸铵沉淀从内源性大肠杆菌植酸酶中分离出异源表达的植酸酶。该酶在50℃和pH 6.5时具有最佳活性。
