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Cytochrome bd oxidase from Escherichia coli displays high catalase activity: An additional defense against oxidative stress
Author(s) -
Borisov Vitaliy B.,
Forte Elena,
Davletshin Albert,
Mastronicola Daniela,
Sarti Paolo,
Giuffrè Alessandro
Publication year - 2013
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/j.febslet.2013.05.047
Subject(s) - catalase , antimycin a , cytochrome , cyanide , cytochrome c oxidase , chemistry , oxidative stress , biochemistry , heme , escherichia coli , oxidative phosphorylation , cytochrome p450 reductase , reductase , enzyme , hemeprotein , oxygen , microbiology and biotechnology , cytochrome c , biology , coenzyme q – cytochrome c reductase , electron transport chain , mitochondrion , inorganic chemistry , organic chemistry , gene
Cytochrome bd oxygen reductase from Escherichia coli has three hemes, b 558 , b 595 and d . We found that the enzyme, as‐prepared or in turnover with O 2 , rapidly decomposes H 2 O 2 with formation of approximately half a mole of O 2 per mole of H 2 O 2 . Such catalase activity vanishes upon cytochrome bd reduction, does not compete with the oxygen‐reductase activity, is insensitive to NO, CO, antimycin‐A and N ‐ethylmaleimide (NEM), but is inhibited by cyanide ( K i ∼2.5 μM) and azide. The activity, possibly associated with heme‐ b 595 , was also observed in catalase‐deficient E. coli cells following cytochrome bd over‐expression suggesting a protective role against oxidative stress in vivo.