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Caspases are reversibly inactivated by hydrogen peroxide
Author(s) -
Borutaite Vilmante,
Brown Guy C
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02593-5
Subject(s) - hydrogen peroxide , caspase , chemistry , photochemistry , biochemistry , apoptosis , programmed cell death
Hydrogen peroxide (H 2 O 2 ) is known to both induce and inhibit apoptosis, however the mechanisms are unclear. We found that H 2 O 2 inhibited the activity of recombinant caspase‐3 and caspase‐8, half‐inhibition occurring at about 17 μM H 2 O 2 . This inhibition was both prevented and reversed by dithiothreitol while glutathione had little protective effect. 100–200 μM H 2 O 2 added to macrophages after induction of caspase activation by nitric oxide or serum withdrawal substantially inhibited caspase activity. Activation of H 2 O 2 ‐producing NADPH oxidase in macrophages also caused catalase‐sensitive inactivation of cellular caspases. The data suggest that the activity of caspases in cells can be directly but reversibly inhibited by H 2 O 2 .