The Fenton reagent (hydrogen peroxide plus Fe(II) or Fe(III) catalyzes nearly quantitative conversion of amino acids to ammonia and a mixture of aliphatic aldehydes and carboxylic acids containing one less carbon atom. The oxidation is stimulated by bicarbonate ion and additionally by either EDTA, EGTA, o-phenanthroline, Desferal, Ferrozine, DETAPAC, NTA, citrate, or ADP when they are present at concentrations below that required to chelate all of the iron present. With excess chelator, amino acid oxidation occurs only after a lag which corresponds to the time required to reduce (by oxidation) the concentration of chelator to a level slightly below that needed to chelate all of the iron. The results suggest that amino acid oxidation requires the participation of both an iron-chelate and either unchelated iron or a second type of iron complex, possibly one involving bicarbonate ion and/or the amino acid. Low sensitivity of amino acid peroxidation to various radical scavengers indicates that oxygen radicals are either not involved or are generated in situ by peroxidation of an iron-chelate-amino acid complex. The formation of such a complex was established in spectrophotometric studies showing that Fe(II), ferrozine and an amino acid react to form first a ternary complex which subsequently decomposes to yield the typical (ferrozine)3-Fe(II) complex. The amino acid-Fe(II)-ferrozine-complex but not the (ferrozine)3-Fe(II) complex is readily oxidized by hydrogen peroxide.
| Noda, Yasuko; Berlett, Barbara S; Stadtman, Earl R et al. (2007) Identification of enzymes and regulatory proteins in Escherichia coli that are oxidized under nitrogen, carbon, or phosphate starvation. Proc Natl Acad Sci U S A 104:18456-60 |
| Tanaka, Mikiei; Chock, P Boon; Stadtman, Earl R (2007) Oxidized messenger RNA induces translation errors. Proc Natl Acad Sci U S A 104:66-71 |
| Miyoshi, Noriyuki; Oubrahim, Hammou; Chock, P Boon et al. (2006) Age-dependent cell death and the role of ATP in hydrogen peroxide-induced apoptosis and necrosis. Proc Natl Acad Sci U S A 103:1727-31 |
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| Khan, Mohammed A S; Chock, P Boon; Stadtman, Earl R (2005) Knockout of caspase-like gene, YCA1, abrogates apoptosis and elevates oxidized proteins in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 102:17326-31 |
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| Lee, Byung Cheon; Lee, Yong Kwon; Lee, Ho-Joung et al. (2005) Cloning and characterization of antioxidant enzyme methionine sulfoxide-S-reductase from Caenorhabditis elegans. Arch Biochem Biophys 434:275-81 |
| Stadtman, Earl R; Arai, Hirofumi; Berlett, Barbara S (2005) Protein oxidation by the cytochrome P450 mixed-function oxidation system. Biochem Biophys Res Commun 338:432-6 |
| Oubrahim, Hammou; Wang, Jun; Stadtman, Earl R et al. (2005) Molecular cloning and characterization of murine caspase-12 gene promoter. Proc Natl Acad Sci U S A 102:2322-7 |
| Williams, W M; Stadtman, E R; Moskovitz, J (2004) Ageing and exposure to oxidative stress in vivo differentially affect cellular levels of PrP in mouse cerebral microvessels and brain parenchyma. Neuropathol Appl Neurobiol 30:161-8 |
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