Abstract: 【Abstract】 Objective To clone and express a novel gene cDNA fragment, pbmag-1, from Plasmodium berghei ANKA strain. Methods The cDNA sequence of pbmag-1 was obtained from the GenBank of P.berghei ANKA genomic databases, with which a pair of primers was designed and RT-PCR was used to get a cDNA fragment of the gene from the parasite. The expanded cDNA 3′ fragment of the gene was obtained by 3′-RACE using the oligo dT primer and a set of specific primers. The intact cDNA 3′ fragment was cloned into a prokaryotic expressional vector and transformed into the BL21-(DE3)-RIL strain of Escherichia coli. The recombinant protein of PbMAg-1 was expressed with an optimized strategy and used to immunize mice. Results The pbmag-1 cDNA fragment obtained was 1 341 bp in length, A/T rich (73%) and with a correct 3′ end sequence. By Western blot, the anti-serum of mice immunized with the recombinant protein of PbMAg-1/GST, which was expressed as inclusion bodies, specifically recognized a band with Mr 64 000 molecule from the protein extracts of P. berghei-infected mouse erythrocytes. Conclusion The pbmag-1 cDNA sequence with intact 3′ has been obtained, which will be used for further study on its role in the immune response of P. berghei infection.

Key words: pbmag-1, Plasmodium berghei, Gene cloning, Prokaryotic expression