• Home
  • Search Results
  • Cytochrome bd from Escherichia coli catalyzes peroxynitrite decomposition.

Cytochrome bd from Escherichia coli catalyzes peroxynitrite decomposition.

Biochimica et biophysica acta (2014-12-03)
Vitaliy B Borisov, Elena Forte, Sergey A Siletsky, Paolo Sarti, Alessandro Giuffrè

Cytochrome bd is a prokaryotic respiratory quinol oxidase phylogenetically unrelated to heme-copper oxidases, that was found to promote virulence in some bacterial pathogens. Cytochrome bd from Escherichia coli was previously reported to contribute not only to proton motive force generation, but also to bacterial resistance to nitric oxide (NO) and hydrogen peroxide (H2O2). Here, we investigated the interaction of the purified enzyme with peroxynitrite (ONOO(-)), another harmful reactive species produced by the host to kill invading microorganisms. We found that addition of ONOO(-) to cytochrome bd in turnover with ascorbate and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) causes the irreversible inhibition of a small (≤15%) protein fraction, due to the NO generated from ONOO(-) and not to ONOO(-) itself. Consistently, addition of ONOO(-) to cells of the E. coli strain GO105/pTK1, expressing cytochrome bd as the only terminal oxidase, caused only a minor (≤5%) irreversible inhibition of O2 consumption, without measurable release of NO. Furthermore, by directly monitoring the kinetics of ONOO(-) decomposition by stopped-flow absorption spectroscopy, it was found that the purified E. coli cytochrome bd in turnover with O2 is able to metabolize ONOO(-) with an apparent turnover rate as high as ~10 mol ONOO(-) (mol enzyme)(-1) s(-1) at 25°C. To the best of our knowledge, this is the first time that the kinetics of ONOO(-) decomposition by a terminal oxidase has been investigated. These results strongly suggest a protective role of cytochrome bd against ONOO(-) damage.

Product Number
Product Description

DL-Dithiothreitol solution, BioUltra, for molecular biology, ~1 M in H2O
DL-Dithiothreitol solution, 1 M in H2O
Diethylenetriaminepentaacetic acid, ≥99% (titration)
Diethylenetriaminepentaacetic acid, ≥98% (titration)
Coenzyme Q1, ≥95%
Diethylenetriaminepentaacetic acid, for complexometry, ≥99.0%
N,N,N′,N′-Tetramethyl-p-phenylenediamine, 99%, powder
N-Lauroylsarcosine, purum p.a., ≥98.0% (GC)
N-Lauroylsarcosine, neat, ≥95%

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon


Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.