Four plasmepsins are active in thePlasmodium falciparumfood vacuole, including a protease with an active-site histidine

Authors:

Abstract
Hemoglobin degradation is a metabolic process that is central to the growth and maturation of the malaria parasitePlasmodium falciparum. Two aspartic proteases that initiate degradation, plasmepsins (PMs) I and II, have been identified and extensively characterized. Eight additional PM genes are present in theP. falciparumgenome. To better understand the enzymology of hemoglobin degradation, it is necessary to determine which of these genes are expressed when hemoglobin degradation is occurring, which encode active enzymes, and which gene products are found in the food vacuole where catabolism takes place. Our genome-wide analysis reveals that PM I, II, and IV and histo-aspartic protease encode hemoglobin-degrading food vacuole proteases. Despite having a histidine in place of one of the catalytic aspartic acids conserved in other aspartic proteases, histo-aspartic protease is an active hydrolase.

This publication has 32 references indexed in Scilit: