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Hydrogen Peroxide‐mediated Inactivation of Two Chloroplastic Peroxidases, Ascorbate Peroxidase and 2‐Cys Peroxiredoxin †
Author(s) -
Kitajima Sakihito
Publication year - 2008
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2008.00452.x
Subject(s) - peroxidase , hydrogen peroxide , chemistry , peroxiredoxin , biochemistry , catalase , enzyme , peroxide , organic chemistry
Reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide, are generated by the photosystems because photoexcited electrons are often generated in excess of requirements for CO 2 fixation and used for reducing molecular oxygen, even under normal environmental conditions. Moreover, ROS generation is increased in chloroplasts if plants are subjected to stresses, such as drought, high salinity and chilling. Chloroplast‐localized isoforms of ascorbate peroxidase and possibly peroxiredoxins assume the principal role of scavenging hydrogen peroxide. However, in vitro studies revealed that both types of peroxidases are easily damaged by hydrogen peroxide and lose their catalytic activities. This is one contributing factor for cellular damage that occurs under severe oxidative stress. In this review, I describe mechanisms of hydrogen peroxide‐mediated inactivation of these two enzymes and discuss a reason why they became susceptible to damage by hydrogen peroxide.