Abstract: 　　[Abstract] Objective   To construct the prokaryotic expression vector for HD-5and purify the recombinant HD-5 protein then analyze its antifungal activity.Methods   The HD-5gene was cloned by PCR, then was inserted into prokary?otic expression plasmid pQE-30Xa to construct pQE-30Xa/HD-5. After sequencing, pQE-30Xa/HD-5 gene was transformed in?toE.coliM15cells. Its expression was induced by IPTG and confirmed by SDS-PAGE. The recombinant protein was purified through Ni-NTA affinity purification system. The antifungal activity was tested by disk diffusion method. Results   HD-5 gene and pQE-30Xa/HD-5vector were obtained successfully.E.coli M15strains was used to express HD-5fusion protein.After purification, the fusion protein was confirmed by Western blot. The disk diffusion test confirmed that the fusion pro?tein can inhibit Candida albicans. Conclusion   Expression vector pQE-30Xa/HD-5was successfully constructed. The HD-5fusion protein was expressed inE.colisuccessfully, which showed a certain degree of antifungal activity.

Key words: defensins, recombinant fusion proteins, Escherichia coli, Human alpha defensin 5, prokaryotic expression, affinity purification, antifungal activity