Expression and immunocompetence identification of Plasmodium falciparum glutamate dehydrogenase.

Objective: To express the fusion protein of glutamate dehydrogenase (GDH) with glutathione S-transferase (GST) of Plasmodium falciparum FCC1/HN in E. coli BL21 and assess the immunocompetence of the recombinant protein.

Methods: GDH gene of P. falciparum was specifically amplified with PCR, followed by double enzyme digestion and cloning the gene fragment into pGEX-4T-1 vector for the expression of the fusion protein GST. The recombinant plasmid was transformed into E. coli BL21. Four mice (Kunming strain) were immunized with purified recombinant protein (antigen) and the polyclonal antibodies produced in response to the treatment were collected. Enzyme-linked immunosorbent assay and Western blotting were carried out to examine the immunocompetence of the recombinant protein.

Results: The fusion protein was successfully expressed, which exhibited specific reaction with the sera obtained from mice immunized with P. falciparum. Specific humoral responses were elicited after introducing the fusion protein in mice and the specific antibody titer was 1:16 in agar diffusion assay.

Conclusion: GDH of P. falciparum may have successful expression in E. coli BL21 and the expressed protein possesses high antigenicity.