In silico targeting of plasmodium falciparum metallo-aminopeptidases using hydroxamate inhibitors

The emergence of Plasmodium falciparum strains resistant to conventional antimalarial medications such as chloroquine, mefloquine, pyrimethamine, and sulfadoxine underscores the urgent need for novel therapeutic agents. Metallo-aminopeptidase PfA-M1, a zinc-dependent enzyme that catalyzes host hemoglobin degradation into heme, represents a validated target for P. falciparum malaria treatment. In the present study, an in-silico molecular approach was applied to evaluate cinnamoyl sulfonamide hydroxamate derivatives (NMJ 1-8) against PfA-M1 (PDB ID: 4X2U, 1.50 Å resolution, Zn²⁺-dependent). Orally available aminopeptidase inhibitor tosedostat bound to the PfA-M1. Extra-precision docking, MMGBSA binding energy analysis, and induced-fit docking demonstrated favorable ligand-protein interactions with IFD docking scores ranging from - 1984.16 to - 1989.93 kcal/mol. Among these, NMJ-2 and NMJ-3 showed the strongest binding affinities and were subjected to molecular dynamics (MD) simulations. The MD results confirmed the formation of stable complexes, highlighting persistent interactions with crucial residues HIS500, GLU463, GLU519, and HIS496. Bioisosteric replacement further optimized NMJ-2 and NMJ-3 derivatives, all of which satisfied ADME pharmacokinetic parameters. Importantly, the interaction patterns of NMJ-2 and NMJ-3 overlapped with those of the reference inhibitor tosedostat, indicating their potential to inhibit PfA-M1 activity in P. falciparum. These findings suggest that NMJ-2 and NMJ-3 are promising scaffolds for future antimalarial drug development and require further preclinical validation.