Sequence diversity of the C-terminal region of Plasmodium falciparum merozoite surface protein 1 in southern Iran.

The C-terminal region of the merozoite surface protein 1 (MSP-1) of Plasmodium falciparum is a strong vaccine candidate as it is associated with immunity to the parasite. This corresponds approximately to the conserved 17th block of the gene and is composed of two EGF- like domains. These domains exhibit only four single amino acid substitutions which show several potential variants in this region of the gene. As the variations might be important for a regional vaccine design, a study was carried out to determine the variations present in P. falciparum isolates from southern Iran. Besides the usual E-T-S-R-L and the Q-K-N-G-F types, we found Q-T-S-R-L, E-K-N-G-F, E-T-S-G-L, Z-T-S-G-L and Z-T-S-R-L types, where Z was E or Q signifying the presence of mixed clones in single isolates.