Publication Date:
1988-06-03
Description:
A major portion of the toxicity of hydrogen peroxide in Escherichia coli is attributed to DNA damage mediated by a Fenton reaction that generates active forms of hydroxyl radicals from hydrogen peroxide, DNA-bound iron, and a constant source of reducing equivalents. Kinetic peculiarities of DNA damage production by hydrogen peroxide in vivo can be reproduced by including DNA in an in vitro Fenton reaction system in which iron catalyzes the univalent reduction of hydrogen peroxide by the reduced form of nicotinamide adenine dinucleotide (NADH). To minimize the toxicity of oxygen radicals, the cell utilizes scavengers of these radicals and DNA repair enzymes. On the basis of observations with the model system, it is proposed that the cell may also decrease such toxicity by diminishing available NAD(P)H and by utilizing oxygen itself to scavenge active free radicals into superoxide, which is then destroyed by superoxide dismutase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Imlay, J A -- Linn, S -- New York, N.Y. -- Science. 1988 Jun 3;240(4857):1302-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of California, Berkeley.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3287616" target="_blank"〉PubMed〈/a〉
Keywords:
Chemical Phenomena
;
Chemistry
;
*DNA Damage
;
DNA, Bacterial/*drug effects
;
Escherichia coli/drug effects/*genetics
;
Free Radicals
;
Hydrogen Peroxide/*pharmacology
;
Iron
;
NAD/metabolism
;
Oxidation-Reduction
;
Oxygen/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
