幽门螺杆菌过氧化氢酶基因的克隆、高效表达及活性评价

Cloning, expression and activity of catalase gene of H.pylori

目的 构建高效表达幽门螺杆菌 (Hp)过氧化氢酶重组蛋白的候选菌株并测定其活性。方法 用PCR方法从Hp染色体DNA上扩增过氧化氢酶基因 ,将其定向插入表达载体 pET 2 2b(+)中 ,并在BL2 1(DE3)大肠杆菌中表达 ,进一步利用贝尔斯 西策尔斯法测定其活性。结果 DNA序列分析表明 ,所克隆的过氧化氢酶基因序列与基因库公布的一致。在 37°C诱导表达 3h后 ,过氧化氢酶重组蛋白表达量占菌体总蛋白的 2 4 .4 % ,并显示了良好的活性。结论 本研究获得了表达高活性Hp过氧化氢酶的克隆 ,为深入研究其相关功能奠定了良好基础。

Objective To construct a highly expresses catalase of Helicobacter pylori (H.pylori) and to test it's activity. Methods The catalase DNA was amplified from H.pylori chromosomal DNA by PCR techniques, inserted into the prokaryotie expression vector pET 22b(+) and then transformed into the BL21(DE3) E.coli strain which expressed catalase recombinant protein. Then the activity of H.pylori catalase was assayed by the Beers and Sizers. Results DNA sequence analysis showed that the sequence of catalase DNA was the same as that published by GenBank. The catalase recombinant protein amounted to 24.4% of the total bacterial protein after inducing with IPTG for 3 hours at 37°C and the activity of H.pylori catalase was high in the BL21 (DE3) E.coli strain. Conclusions A clone of expressing high activity H.pylori catalase has been obtained, and thus a good foundation for further study has been laid.