| DOI | Resolve DOI: https://doi.org/10.1016/S0891-5849(00)00298-7 |
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| Author | Search for: Hodges, G.R.1; Search for: Young, M.J.1; Search for: Paul, T.1; Search for: Ingold, K. U.1 |
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| Affiliation | - National Research Council of Canada
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| Format | Text, Article |
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| Subject | acetaldehyde; cytochrome c oxidase; hydrogen peroxide; superoxide; tetranitromethane; xanthine oxidase; chemical analysis; chemical reaction; competitive inhibition; electron transport; proton transport; reduction; acetaldehyde; comparative Study; cytochrome c; indicators and reagents; kinetics; milk; oxidation-reduction; spectrophotometry; superoxides; support, non-U.S. Gov't; tetranitromethane; xanthine oxidase |
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| Abstract | The rate of formation of superoxide measured by its reduction of tetranitromethane (TNM) and by its reduction of ferric cytochrome c (Fe(III) cc) are in excellent agreement when the superoxide is generated from a simple chemical precursor. In contrast, the rate of formation of superoxide generated in the reaction of xanthine oxidase with acetaldehyde is much higher (up to a factor of 6) when measured with TNM and compared with Fe(III) cc. It is shown that Fe(III) cc measures superoxide that has diffused from the enzyme, and that TNM probably scavenges all the dioxygen that is reduced by one electron by the enzyme. The TNM traps enzyme-bound superoxide in competition with the second-electron transfer and proton transfer, which normally yield hydrogen peroxide. The proton transfer is probably rate determining, k(p) ≤ 3.8 x 103s-1. (C) 2000 Elsevier Science Inc. |
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| Publication date | 2000 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 21276687 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 417cf1e6-505f-4c1d-91ad-5741dd5b8c07 |
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| Record created | 2015-10-13 |
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| Record modified | 2020-03-26 |
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