Cytochrome bd oxidase from Escherichia coli displays high catalase activity: an additional defense against oxidative stress.

Vitaliy B Borisov (1) , Elena Forte (2) , Albert Davletshin (1) , Daniela Mastronicola (3) , Paolo Sarti (2) , Alessandro Giuffrè (3)

1 Belozersky Institute of Physico-Chemical Biology
2 Department of Biochemical Sciences "Rossi Fanelli"
3 CNR - National Research Council of Italy -

Cytochrome bd oxygen reductase from Escherichia coli has three hemes, b558, b595 and d. We found that the enzyme, as-prepared or in turnover with O2, rapidly decomposes H2O2 with formation of approximately half a mole of O2 per mole of H2O2. 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 (Ki ~2.5μM) and azide. The activity, possibly associated with heme-b595, was also observed in catalase-deficient E. coli cells following cytochrome bd over-expression suggesting a protective role against oxidative stress in vivo.

Domains: Biochemistry, Molecular Biology

Vitaliy B Borisov, Elena Forte, Albert Davletshin, Daniela Mastronicola, Paolo Sarti, et al.. Cytochrome bd oxidase from Escherichia coli displays high catalase activity: an additional defense against oxidative stress.. FEBS Letters, 2013, 587 (14), pp.2214-8. ⟨10.1016/j.febslet.2013.05.047⟩. ⟨pasteur-01054294⟩