Abstract: Objective: To express the major epitopes domain of herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) in prokaryotic expression system. The fusion protein was purified and its immunogenicity was studied. Methods: The potential epitopes of HSV-1 gD were predicted using the software Protean of Lasergen 7.0. Then gD major epitopes domain (gD MED) was chosen based on the prediction results, whose cDNA sequence was synthesized and inserted into the prokaryotic expression vector pET-GST. The recombinant gD MED protein was expressed in E.coli BL21(DE3) pLysS with the induction of Isopropyl-β-D-1-Thiogalactopyrano -side (IPTG) and purified with GST?Bind purification kit. The immunological activity was analyzed by western blot. Results: HSV-1 gD MED was located at 266~394 region according to prediction results, whose cDNA sequence was synthesized and its prokaryotic expression vector pET-GST-gD MED was constructed successfully. The fusion gD MED protein could be expressed in soluble form, and its molecular weight (approximately 45 ku) was very close to predicted value. After purification, the purity quotient of the recombinant protein was over 95%. Western blot analysis revealed that the recombinant protein had immunological activity. Conclusions: HSV-1 gD MED fusion protein with immunological activity was expressed and purified, which would be helpful to prepare HSV immunologic diagnosis kit and genetically engineering vaccine.

Key words: herpes simplex virus type 1, glycoprotein D, major epitopes domain, prokaryotic expression