Plasmodium falciparum ferriprotoporphyrin IX (heme) (FP-IX)

Plasmodium falciparum ferriprotoporphyrin IX (heme) is a toxic byproduct generated during the intraerythrocytic stage of the malaria parasite's life cycle as it digests host hemoglobin (PubMed: 8660487). To prevent cellular damage, the parasite detoxifies free heme by sequestering it into an insoluble crystalline polymer called hemozoin within its acidic food vacuole (Wikipedia: Hemozoin). This process is a vital therapeutic target; quinoline antimalarials like chloroquine bind to heme and inhibit its crystallization, causing toxic heme accumulation that leads to parasite death (PubChem: Chloroquine). Furthermore, artemisinin and its derivatives are activated by the iron center of heme or other intra-parasitic iron sources, triggering the release of free radicals that alkylate parasite proteins and lipids (PubMed: 11511517). Understanding the dynamics of heme sequestration and iron-mediated drug activation remains central to developing treatments against drug-resistant malaria strains (NIH: Malaria).

Other names

HemeFerriprotoporphyrin IXHemozoin precursorIntra-parasitic iron centersMalaria pigment precursor

Inhibition of hemozoin biocrystallization and activation of endoperoxide drugs via iron-mediated radical formation.