Sequence analysis and genotypes of glutamate rich protein of Plasmodium falciparum isolates from different malaria endemic areas in China.

OBJECTIVE

To sequence the gene encoding glutamate rich protein (GLURP) and identify the genotypes of geographically different Plasmodium falciparum (P. f) isolates from China.

METHODS

The gene of R2 repeat region of GLURP was amplified by nested polymerase chain reaction and cloned into T-vector. The nucleotide sequence of GLURP gene was determined by automatic sequencer (Dideoxy termination method) and analyzed by DNA Star software.

RESULTS

At least 7 different GLURP genotypes ranging from 600 bp to 1,500 bp were found in Yunnan and Hainan provinces. R2 region of GLURP gene consisted of several repeat units. Each repeat unit was composed of 19-20 residues which were shown to be highly conserved. GLURP gene was also size polymorphic due to differences in the number of repeat units, whereas the repeat sequence was conserved. Sequence analysis showed that DNA sequences and deduced amino acid sequences were highly homologous among the geographically dispersed isolates or various isolates from the same geographical region. No obvious differences were found in the GLURP gene sequences among geographically different isolates.

CONCLUSION

GLURP gene is highly structure conserved and size polymorphic, and so is useful in searching for malaria vaccine candidate antigen and developing a genotyping method for malaria research.