Multi-omics Based Identification of Specific Biochemical Changes Associated With PfKelch13-Mutant Artemisinin-Resistant Plasmodium falciparum

Background. The emergence of artemisinin resistance in the malaria parasite Plasmodium falciparum poses a major threat to the control and elimination of malaria. Certain point mutations in the propeller domain of PfKelch13 are associated with resistance, but PfKelch13 mutations do not always result in clinical resistance. The underlying mechanisms associated with artemisinin resistance are poorly understood, and the impact of PfKelch13 mutations on cellular biochemistry is not defined. Methods. This study aimed to identify global biochemical differences between PfKelch13-mutant artemisinin-resistant and -sensitive strains of P.falciparum by combining liquid chromatography-mass spectrometry (LC-MS)-based proteomics, peptidomics, and metabolomics. Results. Proteomics analysis found both PfKelch13 mutations examined to be specifically associated with decreased abundance of PfKelch13 protein. Metabolomics analysis demonstrated accumulation of glutathione and its precursor, gamma-glutamylcysteine, and significant depletion of 1 other putative metabolite in resistant strains. Peptidomics analysis revealed lower abundance of several endogenous peptides derived from hemoglobin (HB alpha and HB beta) in the artemisinin-resistant strains. Conclusion. PfKelch13 mutations associated with artemisinin resistance lead to decreased abundance of PfKelch13 protein, decreased hemoglobin digestion, and enhanced glutathione production.