Abstract:

Objective  To clone and express the DBL domain of Plasmodium falciparum merozoite surface protein MSPDBL2（DBL2）, and investigate its antigenicity.  Methods  The DBL2 fragment was amplified by PCR and cloned into pET28a vector. The recombinant pET28a-DBL2 plasmid was transformed into E. coli BL21（DE3） and protein expression was induced by IPTG. The expressed product was purified by Ni-NTA affinity chromatography, and analyzed by SDS-PAGE and Western blotting.  Results  DBL2 gene fragment of Plasmodium falciparum merozoite surface protein MSPDBL2（950 bp） was obtained by PCR. The recombinant pET28a-DBL2 plasmid was identified by PCR， double enzyme digestion, and DNA sequencing. The recombinant DBL2 protein was expressed in an inclusion body form with Mr 340 000 after being induced with IPTG. Moreover, the purified recombinant DBL2 protein was recognized by sera from patients with falciparum malaria.  Conclusion  The recombinant pET28a-DBL2 plasmid has been constructed. The purified rDBL2 protein shows adequate antigenicity.

Key words: Plasmodium falciparum, Merozoite, Prokaryotic expression, Antigenicity