Expression and Immunogenicity of a Repeated Tripeptide Region of P190 Antigen in Plasmodium falciparum
恶性疟P190抗原基因的表达及免疫学研究

A DNA fragment, designated as P190TR, encoding amino acid residues of the tripeptide region of the P190 antigen was amplified by Polymerase Chain Reaction from genomic DNA of FCCL/HN Plasmodium falciparum isolated from Hainan province, China. Upon comparison with the nucleotide sequences of MAD20 strain, It was found that there were five bases substitution in the P190TR. The DNA fragment seqenced were ligated to BamHI-digested pGEX-2T vector. Competent E. coli JM109 (DE3) were transformed with either parental or recombinant pGEX-2T for expression. Analysis of the soluble cellular proteins revealed the high level expression of GST-P190TR as fusion protein. Affinity purification of the fusion protein under nondenaturing condition resulted in the removal of almost all other E. coli protein. The purified GST-P190TR was used as an immunogen in rabbits. The antibodies against the recombinant protein was raised and the highest liter as measured by IFA was 1: 320.