Abstract
In malaria, Plasmodium parasites produce hemozoin (Hz) as a route to detoxify free heme released from the catabolism of hemoglobin. Hz isolated from the parasites is encapsulated in an organic layer constituted by parasite and host components. This organic coating may play a role in Hz formation and in the immunomodulatory properties attributed to Hz, and they may influence the mode of action of antimalarials that block Hz formation. In this work, we analyze the organic layer adhered to Hz, and find Na, Cl, Si, Ca and P present, in addition to organic material. Our results suggest that Na, Cl, and P adsorb during Hz release from the red blood cells, while Si and Ca derive from components present during Hz biomineralization within the digestive vacuole of the parasite. Overall, we show that inorganic elements associated with Hz surface provide insights into the biological functions of Plasmodium parasites.
Hemozoin crystals collected from malaria parasites present inorganic elements of silicon, calcium, phosphorus, sodium, and chlorine, in addition to organic material. The speciation of the inorganic elements is discussed and points out to unexplored functions in Plasmodium's biology and possibly other Apicomplexan parasites. [Display omitted]
•Inorganic ions are associated with the organic coating adsorbed on hemozoin surface.•Sodium, chlorine and phosphorus adsorb during hemozoin release from the red blood cells.•Silicon and calcium derive from components present within the parasite.•Silicon is present as silica and, likely, silicon bound to cellular components.•These ions may be related to yet unexplored biological functions of the parasite.