Gene disruption confirms a critical role for the cysteine protease falcipain-2 in hemoglobin hydrolysis by Plasmodium falciparum.

ABSTRACT: Erythrocytic malaria parasites degrade hemoglobin in an acidic food vacuole to acquire free amino acids and maintain parasite homeostasis. Hemoglobin hydrolysis appears to be a cooperative process requiring cysteine proteases (falcipains) and aspartic proteases (plasmepsins), but the specific roles of different enzymes in this process are unknown. We previously showed that falcipain-2 is a major trophozoite food vacuole cysteine protease. To characterize the specific role of falcipain-2, we disrupted the falcipain-2 gene and assessed the effect of this alteration. Falcipain-2-knockout trophozoites had markedly diminished cysteine protease activity and swollen, dark staining food vacuoles, consistent with a block in hemoglobin hydrolysis, as caused by cysteine protease inhibitors. However,

SUBMITTER: Sijwali PS 

PROVIDER: S-EPMC384756 | biostudies-literature | 2004 Mar

REPOSITORIES: biostudies-literature