The overexpression of Plasmodium falciparum M1 aminopeptidase promotes an increase in intracellular proteolysis and modifies the development of the asexual erythrocytic cycle

Plasmodium falciparum, the most virulent parasite of human malaria, is responsible for high mortality rates worldwide. The overPfA-M1 parasites showed a 2.5-fold increase in proteolytic activity in relation to the fluorogenic substrate alanyl-7-amido-4-methylcoumarin, in relation to the wild group. Inhibition studies showed that overPfA-M1 showed lower sensitivity against the metalloaminopeptidase in-hibitor bestatin and other recombinant PfA-M1 inhibitors compared to the wild-type strain, indicating that PfA-M1 is a target for antimalarial activity in in vitro of these compounds. Furthermore, overPfA-M1 parasites show a decrease in growth in vitro, showing a reduced number of merozoites per schizont, and also a decrease in the iRBC area occupied by the parasite in trophozoite and schizont forms when compared to controls. Interestingly, the transgenic parasite exhibits an increase in aminopeptidase activity for Met-, Ala-, Leu- and Arg-7-amido-4-methylcoumarin. The potential role of calmodulin and cysteine proteases in PfA-M1 activity was also investigated. Taken together, the data show that the overexpression of PfA-M1 in the cytosol of the parasite can be a suitable tool for screening antimalarials in specific high-throughput assays and can be used for the identification of intracellular molecular partners that modulate their activity in P. falciparum. 

Project details

Basic Science

Dec 2021 — May 2022

Brazil