Abstract
Electron spin resonance measurements provide evidence for the formation of long-lived Cr(V) intermediates in the reduction of Cr(VI) by glutathione reductase in the presence of NADPH and for the hydroxyl radical formation during the glutathione reductase catalyzed reduction of Cr(VI). Hydrogen peroxide suppresses Cr(V) and enhances the formation of hydroxyl radicals. Thus Cr(V) intermediates catalyze generation of hydroxyl radicals from hydrogen peroxide through a Fenton-like reaction. Thus the mechanism of Cr(VI) toxicity might involve the interaction between macromolecules and the hydroxyl radicals.
Original language | English |
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Pages (from-to) | 627-634 |
Number of pages | 8 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 163 |
Issue number | 1 |
DOIs | |
State | Published - Aug 30 1989 |
Bibliographical note
Funding Information:C(V1) compounds have been found to exert serious toxic and carcinogenic effects on humans and animals (l-31. In contrast, most Cr(III1 compounds are relatively nontoxic, noncarcinogenic, and nonmutagenic (1,41. Cr(VI1 and Cr(II1) oxidation states are different in their metabolic pathways: Cr(V1) ions are rapidly transported across cellular membrane (1,4,51, while CrlIIIl moieties do not easily penetrate cells and are not oxidized by cellular constituents (Il. Since it is known that the reduction of Cr(VI1 ion is required for its reaction with DNA (11, the molecular mechanisms for the intracellular Cr(VI1 reduction has been the focus of current studies but the details are still not understood. Earlier studies on the mechanism of Cr(VI1 reduction include those on the reduction of CrIVIl by glutathione (GSH) (1.6-81, ascorbic acid (91, glucose (101, lactose (101, galacturonic acid (111, microsome (121, and mitochondrial electron transport chain complexes (131. These studies have shown that the Cr(VI1 reduction involves the formation of Cr(V)-containing species which are often considered to be the toxic form of chromium. Thus far, however, no information is available on the subsequent fate of those biologically formed ‘Part of this research has been supported by the Department of the Interior’s Mineral Institute program administered by the Bureau of Mines through the Generic Mineral Technology Center for Respirable Dust under grant G1135142.
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology