中文摘要：

本研究将碳酸酐酶Dca片段插入原核表达载体pET21b中并转化大肠杆菌OrigamiB（DE3）pLysS，由IPTG诱导表达带有组氨酸标签的融合蛋白，并经镍柱亲和层析方法获得纯化的Dca，通过p-Nitrophenyl Acetate测活（pNPA）结果显示具有活性，为Dca结构与功能的研究提供了足量的蛋白质保证．纯化出的蛋白质利用Edelhoch方法测定其摩尔消光系数（molar absorbance coefficient）ε，结果显示比预测的摩尔消光系数值偏小．

英文摘要：

To obtain stable, active recombinant Dca and provide a accurate concentration determination for the subsequent research, full length cDNA of Dca was constructed into prokaryotic expression vector pET21b and the recombinant plasmid was transferred into Origami B（DE3）pLysS. Expression of the target protein was induced with IPTG and purified under native conditions using the Ni-NTA agarose column. The activity of Dca was verified through the enzymatic assay with pNPA（p-Nitrophenyl Ace-tate） and the production of enough Dca paves the way for the functional and structural study. Based on the Edelhoch method, ε（molar absorbance coefficient） was determined and the measurement of Dca of- fers an accurate concentration determination of this protein in pursuing detailed studies.