Abstract: Objective：To clone the Helicobacter pylori (Hp) thioredoxin-1 (Trx1) gene and construct the recombinant expression vector containing the target gene, then to express and purify the protein, and detect its activity. Methods：The cDNA gene of the Hp Trx1 was amplified by RT-PCR from the international standard strain 26695, using the specific primers containing double endonuclease digesting sites. The Hp Trx1 cDNA was then inserted into the pEASY-T1 vector to construct the pEASY-T1-Hp Trx1 recombinant vector. The next step was to double digest the pEASY-T1-Hp Trx1 recombinant vector and insert the target gene into pET-30a to construct the pET-30a-Hp Trx1 recombinant vector, which was transferred to E.coli BL21 plys S to express the Hp Trx1 protein. The recombinant protein was purified by Ni affinity chromatography, and then its activity of disulfide reductase was detected. Results：By DNA sequencing, the Hp Trx1 cDNA was successfully inserted into the pET-30a vector and was in accordance with GenBank(HP0824). The E.coli containing pET-30a-Hp Trx1 recombinant vector successfully expressed Hp Trx1 protein. Through the detection of the activity, the recombinant Hp Trx1 protein was identified to have the activity of disulfide reductase. Conclusion：The prokaryotic expression vector pET-30a-Hp Trx1 was successfully constructed. The recombinant protein Hp Trx1 was successfully expressed and purified, which had the activity of disulfide reductase. This study lays the foundation for further research on the biological activity of Hp Trx1 and the mechanism of its function in tumor genesis.

Key words: Helicobacter pylori, Thioredoxins, Recombinant proteins, Genetic vectors