Abstract: The aim of this study is to construct a prokaryotic expression vector for pedA gene of pediocin PA-1 to realize the exogenous expression of PA-1，and to analyze the physicochemical properties and molecular structure of recombinant protein by bioinformatics. The pedA gene was amplified by DNA of Pediococcus pentosaceus C-2-1 as template，and the PCR product was cloned into prokaryotic expression vector pET28a（+）. The recombinant plasmid pET28a-pedA was thus constructed and transformed into Escherichia coli BL21（DE3）competent cells. Next，the transformant was induced to express protein by IPTG（1 mmol/L）at 30℃ for 5 h. Then，the recombinant protein was purified by Ni-NTA resin affinity chromatography，and the antibacterial activity of the recombinant protein was detected. Finally，the physicochemical properties and molecular structure of recombinant protein was explored by bioinformatics method. The results showed that the recombinant plasmid pET28a-pedA was successfully constructed，and recombinant pediocin of PA-1 with His-tag was expressed in E. coli. The molecular size of the purified recombinant protein by Ni-NTA affinity chromatography was determined to be about 7.8 kD via Tricine-SDS-PAGE，which was consistent with the theoretical value. Agar diffusion method demonstrated that antibacterial colony was remarkable，indicating that the purified recombinant pediocin had antibacterial activity. Comparative analysis of the protein structure and characteristics by bioinformatics method showed that the recombinant protein contained the signal peptide and consisted of 23.53% alpha helix，meaning that its hydrophobicity increased，thus which might enhance the soluble expression of the recombinant protein. Conclusively，in this experiment，the prokaryotic expression vector of pediocin PA-1 was successfully constructed，and the recombinant protein was at soluble expression in E. coli. The soluble expression may be related to signal peptide and the hydrophobicity of the signal peptide，and the antibacterial activity of the purified recombinant protein was significant.

Key words: pedA gene, pediocin PA-1, prokaryotic expression, antibacterial activity, bioinformatics