RESUMO
Background: The ability to predict and comprehend molecular interactions offers significant insights into the biological functions of proteins. The interaction between surface protein 47 of Plasmodium falciparum (Pfs47) and receptor of the protein 47 (P47Rec) has attracted increased attention due to their role in parasite evasion of the mosquito immune system and the concept of geographical coevolution between species. The aims of this study were as follows: to apply a bioinformatics approach to investigate the interaction between Pfs47 and P47Rec proteins and to identify the potential binding sites, protein orientations and receptor specificity sites concerning the geographical origins of the vectors and the parasite. Methods: Public sequences of the pfs47 and p47rec genes were downloaded and subsequently filtered to predict functional and structural annotations of the Pfs47-P47Rec complex. Phylogenetic analyses of both proteins were carried out. In addition, the p47Rec gene was subjected to sequencing and subsequent analysis in 2 distinct Anopheles species collected in Honduras. Results: The examination of motifs reveals a significant degree of conservation in pfs47, suggesting that Pfs47 might have undergone recent evolutionary development and adaptation. Structural models and docking analyses supported the theory of selectivity of Plasmodium falciparum strains towards their vectors in diverse geographical regions. A detailed description of the putative interaction between the Pfs47-P47Rec complex is shown. Conclusions: The study identifies coevolutionary patterns between P47Rec and Pfs47 related to the speciation and geographic dispersion of Anopheles species and Plasmodium falciparum, with Pfs47 evolving more recently than P47Rec. This suggests a link between the parasite's adaptability and existing anopheline species across different regions. P47Rec likely has a cytoplasmic localization due to its lack of membrane attachment elements. However, these findings are based on simulations and require validation through methods like cryo-electron microscopy. A significant limitation is the scarcity of sequences in global databases, which restricts precise interaction modelling. Further research with diverse parasite isolates and anopheline species is recommended to enhance understanding of these proteins' structure and interaction.
RESUMO
The elimination of malaria requires strengthening diagnosis and offering adequate and timely treatment. Imported cases of falciparum malaria represent a major challenge for pre-elimination areas, such as Central America, where chloroquine and primaquine continue to be used as first-line treatment. The pfs47 gene has been previously described as a precise molecular marker to track the geographic origin of the parasite. The aim of this study was to design a simple and low-cost technique using the polymorphic region of pfs47 to assess the geographic origin of P. falciparum strains. A PCR-RFLP technique was developed and evaluated using the MseI enzyme that proved capable of discriminating, with reasonable precision, the geographical origin of the parasites. This method could be used by national surveillance laboratories and malaria elimination programs in countries such as Honduras and Nicaragua in cases of malaria where an origin outside the Central American isthmus is suspected.