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Electrochemical Monitoring of the Early Events of Hydrogen Peroxide Production by Mitochondria
Author(s) -
Suraniti Emmanuel,
BenAmor Salem,
Landry Pauline,
Rigoulet Michel,
Fontaine Eric,
Bottari Serge,
Devin Anne,
Sojic Neso,
Mano Nicolas,
Arbault Stéphane
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201403096
Subject(s) - mitochondrion , redox , hydrogen peroxide , reactive oxygen species , respiratory chain , oxidative phosphorylation , chemistry , biophysics , oxygen , peroxidase , electrochemistry , respiration , cellular respiration , biochemistry , microbiology and biotechnology , electrode , enzyme , biology , inorganic chemistry , organic chemistry , anatomy
Abstract Mitochondria consume oxygen in the respiratory chain and convert redox energy into ATP. As a side process, they produce reactive oxygen species (ROS), whose physiological activities are still not understood. However, current analytical methods cannot be used to monitor mitochondrial ROS quantitatively and unambiguously. We have developed electrochemical biosensors based on peroxidase‐redox polymer‐modified electrodes, providing selective detection of H 2 O 2 with nanomolar sensitivity, linear response over five concentration decades, and fast response time. The release of H 2 O 2 by mitochondria was then monitored under phosphorylating or inhibited respiration conditions. We report the detection of two concomitant regimes of H 2 O 2 release: large fluxes (hundreds of n M ) under complex III inhibition, and bursts of a few n M immediately following mitochondria activation. These unprecedented bursts of H 2 O 2 are assigned to the role of mitochondria as the hub of redox signaling in cells.