This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by McLaggan, D.
Right arrow Articles by Booth, I. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by McLaggan, D.
Right arrow Articles by Booth, I. R.
Agricola
Right arrow Articles by McLaggan, D.
Right arrow Articles by Booth, I. R.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, April 2000, p. 1393-1399, Vol. 66, No. 4
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Glutathione-Dependent Conversion of N-Ethylmaleimide to the Maleamic Acid by Escherichia coli: an Intracellular Detoxification Process

D. McLaggan,1 H. Rufino,1 M. Jaspars,2 and I. R. Booth1,*

Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD,1 and Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE,2 United Kingdom

Received 4 October 1999/Accepted 18 January 2000

The electrophile N-ethylmaleimide (NEM) elicits rapid K+ efflux from Escherichia coli cells consequent upon reaction with cytoplasmic glutathione to form an adduct, N-ethylsuccinimido-S-glutathione (ESG) that is a strong activator of the KefB and KefC glutathione-gated K+ efflux systems. The fate of the ESG has not previously been investigated. In this report we demonstrate that NEM and N-phenylmaleimide (NPM) are rapidly detoxified by E. coli. The detoxification occurs through the formation of the glutathione adduct of NEM or NPM, followed by the hydrolysis of the imide bond after which N-substituted maleamic acids are released. N-Ethylmaleamic acid is not toxic to E. coli cells even at high concentrations. The glutathione adducts are not released from cells, and this allows glutathione to be recycled in the cytoplasm. The detoxification is independent of new protein synthesis and NAD+-dependent dehydrogenase activity and entirely dependent upon glutathione. The time course of the detoxification of low concentrations of NEM parallels the transient activation of the KefB and KefC glutathione-gated K+ efflux systems.

* Corresponding author. Mailing address: Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, United Kingdom. Phone: 44-1224-273152. Fax: 44-1224-273144. E-mail: gen118{at}abdn.ac.uk.

Applied and Environmental Microbiology, April 2000, p. 1393-1399, Vol. 66, No. 4
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Liu, G., Zhou, J., Fu, Q. S., Wang, J. (2009). The Escherichia coli Azoreductase AzoR Is Involved in Resistance to Thiol-Specific Stress Caused by Electrophilic Quinones. J. Bacteriol. 191: 6394-6400 [Abstract] [Full Text]  
  • Mojica, E.-R. E., Kim, S., Aga, D. S. (2008). Formation of N-Ethylmaleimide (NEM)-Glutathione Conjugate and N-Ethylmaleamic Acid Revealed by Mass Spectral Characterization of Intracellular and Extracellular Microbial Metabolites of NEM. Appl. Environ. Microbiol. 74: 323-326 [Abstract] [Full Text]  
  • Fujisawa, M., Ito, M., Krulwich, T. A. (2007). Three two-component transporters with channel-like properties have monovalent cation/proton antiport activity. Proc. Natl. Acad. Sci. USA 104: 13289-13294 [Abstract] [Full Text]  
  • Rawat, M., Uppal, M., Newton, G., Steffek, M., Fahey, R. C., Av-Gay, Y. (2004). Targeted Mutagenesis of the Mycobacterium smegmatis mca Gene, Encoding a Mycothiol-Dependent Detoxification Protein. J. Bacteriol. 186: 6050-6058 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»