Globin-mediated nitric oxide detoxification in the foodborne pathogenic bacterium Campylobacter jejuni proceeds via a dioxygenase or denitrosylase mechanism.

Shepherd, Mark and Bernhardt, Paul V and Poole, Robert K (2011) Globin-mediated nitric oxide detoxification in the foodborne pathogenic bacterium Campylobacter jejuni proceeds via a dioxygenase or denitrosylase mechanism. Nitric Oxide: Biology and Chemistry, 25 (2). pp. 229-33. ISSN 1089-8611. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1016/j.niox.2010.12.006

Abstract

Nitric oxide (NO()) is a toxin, but bacteria have evolved various strategies to detoxify this harmful radical to nitrate, the best known mechanism being the dioxygenase reaction of bacterial flavohaemoglobins. In addition, globins can form oxoferryl (Fe(IV)O) species through the reaction of the ferric haem with hydrogen peroxide: these species can also detoxify NO() to nitrite and nitrate. During infection, Campylobacter is exposed to both NO() and hydrogen peroxide. A question therefore arises: does Campylobacter jejuni utilize its single domain globin (Cgb) to detoxify NO() via the oxoferryl route, or via the more conventional dioxygenase or denitroxylase routes? The data herein demonstrate that the reaction between Cgb and hydrogen peroxide is much slower than for other globins, and subsequent reaction between the oxoferryl species and NO() is unfavourable. Furthermore, NO() may bind to Cgb in the oxyferrous, ferrous and ferric states. The ample opportunity for NO() to interact with ferrous and ferric Cgb, and the unfavourable reaction of ferric Cgb with hydrogen peroxide, suggests that NO() detoxification in C. jejuni proceeds via a dioxygenase or denitroxylase route requiring the haem iron to exist only in the Fe(II) or Fe(III) redox states.

Item Type: Article
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: Mark Shepherd
Date Deposited: 01 Sep 2011 15:48
Last Modified: 10 Jan 2012 11:31
Resource URI: http://kar.kent.ac.uk/id/eprint/28106 (The current URI for this page, for reference purposes)
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