Computational investigation of mutations in PfCRT and PfDHFR proteins for emerging resistance of Plasmodium falciparum to antimalarial drugs.

The emergence of multidrug resistance in Plasmodium falciparum poses a serious threat to antimalarial treatment, particularly with growing resistance to artemisinin-based combination therapies (ACTs) and partner drugs like piperaquine. Mutations in key proteins, such as PfCRT (P. falciparum chloroquine resistance transporter) and PfDHFR (P. falciparum dihydrofolate reductase), play a critical role in this resistance. Understanding these molecular mechanisms is essential for the development of effective antimalarial therapies. This study aimed to investigate the structural and functional impact of polymorphisms on drug-target interactions and resistance mechanisms in P. falciparum. Molecular docking and molecular dynamics (MD) simulations were performed to analyze interactions of the mutated PfCRT and PfDHFR proteins with nine antimalarial drugs, including piperaquine. The PfCRT-K76A piperaquine complex strong binding affinity (-9.5 kcal/mol) with moderate structural deviation (0.970 ± 0.202 nm) and greater solvent accessibility (246.01 ± 6.135 nm²), suggesting favourable binding conditions. The PfDHFR-N51I-piperaquine complex showed even stronger binding (-10.8 kcal/mol) but higher structural fluctuation (RMSD: 4.491 ± 1.462 nm) and increased compactness (1.861 ± 0.029 nm), which may reflect restricted ligand accommodation and possible resistance. Overall, the findings provide valuable insights into how PfCRT and PfDHFR mutations contribute to drug resistance and establish a foundation for designing more effective antimalarial strategies. Future research should integrate experimental validation and explore additional resistance-associated mutations to develop targeted therapies for combating multidrug-resistant P. falciparum.