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

• Published in: FEBS letters 2013-07, Vol.587 (14), p.2214-2218
• Main Authors: Borisov, Vitaliy B., Forte, Elena, Davletshin, Albert, Mastronicola, Daniela, Sarti, Paolo, Giuffrè, Alessandro
• Format: Article
• Language: English
• Subjects: 2,3-dimethoxy-5-methyl-6-(3-methyl-2-butenyl)-1,4-benzoquinone; Animals; Bacteria–host interaction; Biochemistry, Molecular Biology; Catalase; Catalase - chemistry; Cattle; Cytochromes; Cytochromes - antagonists & inhibitors; Cytochromes - chemistry; Dithiothreitol; Dithiothreitol - chemistry; DTT; Electron Transport Chain Complex Proteins; Electron Transport Chain Complex Proteins - antagonists & inhibitors; Electron Transport Chain Complex Proteins - chemistry; Enzyme Inhibitors; Enzyme Inhibitors - chemistry; Escherichia coli; Escherichia coli - enzymology; Escherichia coli Proteins; Escherichia coli Proteins - antagonists & inhibitors; Escherichia coli Proteins - chemistry; Hemeprotein; Hydrogen Peroxide; Hydrogen Peroxide - chemistry; Hydroquinones; Hydroquinones - chemistry; Kinetics; Life Sciences; Microbial metabolism; N-ethylmaleimide; NAD; NAD - chemistry; NAD(P)H Dehydrogenase (Quinone); NAD(P)H Dehydrogenase (Quinone) - chemistry; NEM; Oxidants; Oxidants - chemistry; Oxidative Stress; Oxidoreductases; Oxidoreductases - antagonists & inhibitors; Oxidoreductases - chemistry; Oxygen; Oxygen - chemistry; Rats; Reactive oxygen species; Reducing Agents; Reducing Agents - chemistry; Respiratory chain; ROS; Sodium Cyanide; Sodium Cyanide - chemistry
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2013.05.047

•Cytochrome bd from E. coli displays a notable catalase activity.•Thermal denaturation or complete reduction of cytochrome bd abolishes this activity.•Activity is insensitive to nitric oxide, contrary to bona fide catalases.•A catalase activity is detected in catalase-deficient E. coli upon cytochrome bd over-expression.•A protective role of cytochrome bd against oxidative stress is suggested. 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.