HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Korbashi, P. Articles by Chevion, M. Search for Related Content PubMed PubMed Citation Articles by Korbashi, P. Articles by Chevion, M. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 261, Issue 27, 12472-12476, Sep, 1986

Iron mediates paraquat toxicity in Escherichia coli

P Korbashi, R Kohen, J Katzhendler and M Chevion

The role of iron ions in paraquat toxicity was studied in bacterial system. We show that addition of ferrous iron led to an enhancement of the bacterial killing, whereas addition of chelating agents, such as nitrilotriacetate and desferrioxamine, markedly reduced, up to a total abolishment, the toxic effects. The calculated rates of bacterial killing are proportional to both paraquat and iron concentrations, and conform to the rate equation: dN/dt = -k[paraquat] [Fe2+]. The killing constant for iron, k, is 24-fold smaller than the corresponding value for copper. Mannitol, an OH. scavenger, has a partial protective effect: 15-35% at concentrations range of 1-50 mM, respectively. Histidine, on the other hand, provided a more efficient protection that may be due to a combination of various effects. Induction of endogenous superoxide dismutase and catalase provided partial protection (about 25%). These findings, together with an earlier study on the role of copper in paraquat toxicity (Kohen, R., and Chevion, M. (1985) Free Rad. Res. Commun. 1, 79-88) indicate that transition metals play a central catalytic role in the production of the deleterious effects of paraquat, probably by redox cycling and producing OH. via the site- specific Fenton reaction.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. E. Tindale, M. Mehrotra, D. Ottem, and W. J. Page Dual regulation of catecholate siderophore biosynthesis in Azotobacter vinelandii by iron and oxidative stress Microbiology, July 1, 2000; 146(7): 1617 - 1626. [Abstract] [Full Text]