Ascorbate Peroxidase Acts As a Novel Determiner of Redox Homeostasis in Leishmania

Abstract Significance: Reactive oxygen species (ROS) are produced as natural byproducts of metabolism and respiration. While physiological levels of ROS are required for vital cellular functions (e.g., development and proliferation), a living organism is faced with constant challenges due to accumulation or overproduction of ROS throughout its life. The life cycle of Leishmania parasite has led it to confront the highly oxidizing environment in the macrophage phagosomes, necessitating ROS homeostasis and signaling as key strategies for successful survival and pathogenicity. Recent Advances: Ascorbate peroxidase from Leishmania major (LmAPX) is the only heme peroxidase identified so far in Leishmania. Structural analysis and functional characterization of LmAPX have yielded interesting and novel insight on this enzyme. The protein has been found to be a hybrid of cytochrome c peroxidase and ascorbate peroxidase. This enzyme is colocalized with cytochrome c in the inner mitochondrial membrane facing the int...