Tryparedoxin peroxidases from Trypanosoma cruzi: High efficiency in the catalytic elimination of hydrogen peroxide and peroxynitrite

► Trypanosomacruzi TXNPxs reacted very efficiently with hydrogen peroxide and peroxynitrite. ► Rate constants of H2O2 and peroxynitrite reduction by TcTXNPxs were in the 106-107 M−1 s−1 range. ► mTcTXNPx reacted faster than cTcTXNPx with peroxynitrite. ► Rate constants for the reduction of c-TcTXNPx by TbTXNI was 1.3 × 106 M−1 s−1. ► TcTXNPxs peroxidatic and resolving cysteines identities were confirmed.