Microaerophilic Respiratory Metabolism of Plasmodium falciparum Mitochondrion as a Drug Target

The Plasmodium falciparum mitochondrion is an organelle that presents structural and physiological characteristics different from mitochondria in other eukaryotes. Moreover, there are substantial differences in the properties of asexual and sexual mitochondria. One of the reasons is the adaptation of the parasite to different environments, in particular the great differences in oxygen tension between the host and the mosquito. In this review, we present a synthesis of the recent data on the ultrastructure, the genome and the physiology of the mitochondrion. We try to clarify the mitochondrial role in the intraerythrocytic environment and particularly focus on mitochondrial metabolic pathways that relate to oxidative phosphorylation, including the tricarboxylic acid cycle, de novo pyrimidine biosynthesis via dihydroorotate dehydrogenase and the particularities of the electron transport chain. In addition, we provide details on certain characteristics like the lack of pyruvate dehydrogenase, the existence of a rotenone-insensitive NADH-dehydrogenase, the possible existence of an alternative oxidase, and uncoupled proteins. Such unique particularities of parasite mitochondria could be promising targets for development of a new therapy. The elucidation of the role of this organelle in microaerophilic respiratory metabolism and the association of antimalarial drugs with hyperbaric oxygen therapy might provide new treatments for infection by P. falciparum.