Abstract：Chicken antimicrobial peptides, belong to β-defensins，are essential components of innate immunity and play significant roles in innate immunity in chickens. The cDNA of chicken avian β-defensins 10 (AvBD10) gene was sub-cloned into Sal Ⅰ and NotⅠ sites of AvBD5-pGEX-6p-1 vector to construct recombinant plasmid AvBD5-pGEX-AvBD10. The recombinant plasmid was transferred into Escherichia coli BL21. Then the bacteria was induced with IPTG at 37 ℃ and different time, and exogenous expression was detected by SDS-PAGE. Results showed that a 36 kD protein which was equal to chicken AvBD5-AvBD10 protein in molecular weight was expressed in E.coli BL21. The production of AvBD5-AvBD10 accounted for approximately 35% of the total protein. The recombinant fusion protein was purified and expressed as insoluble body. Two bacterials, E.coli and pathogenic Streptococcus of mid-log (108 cfu/mL) were used to evaluate antibacterial activity of the recombinant fusion protein by inhibition zone assaying. The results showed that the recombinant fusion protein exhibited anti-E.coli. and anti-pathogenic Streptococcus activitiy, and showed high stability at various temperatures -70℃～100 ℃ and pH 3～12.
