Peroxynitrite detoxification by Trypanosoma cruzi heme peroxidase supports parasite survival in macrophages.

ABSTRACT: Trypanosoma cruzi, the causative agent of Chagas disease, must overcome a host's nitro-oxidative burst to establish the infection. Among the reactive species generated by immune cells, peroxynitrite stands out as a highly cytotoxic molecule for the parasite. Yet, the parasite's defense mechanisms against peroxynitrite remain incompletely understood. In this work, we demonstrate that the T. cruzi heme-containing ascorbate peroxidase cytochrome c peroxidase (APx-CcP), an antioxidant enzyme previously shown to increase parasite infectivity, acts as a key peroxynitrite-detoxifying enzyme. Using direct and competitive kinetic assays, we show that APx-CcP reacts rapidly with peroxynitrite (k = 3-4 × 10⁶ M^-1 s^-1 at pH 7.4 and 25 °C) via a two-electron reduction me

SUBMITTER: Skafar V 

PROVIDER: S-EPMC12398798 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature