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Human class Mu glut...
Human class Mu glutathione transferases, in particular isoenzyme M2-2,catalyze detoxication of the dopamine metabolite aminochrome
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- Segura-Aguilar, Juan (author)
- Uppsala universitet,Institutionen för farmaceutisk biovetenskap
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Baez, Sofia (author)
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- Widersten, Mikael (author)
- Uppsala universitet,Institutionen för biokemi och organisk kemi
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- Welch, Christopher J (author)
- Uppsala universitet,Avdelningen för organisk farmaceutisk kemi
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- Mannervik, Bengt (author)
- Uppsala universitet,Institutionen för biokemi och organisk kemi
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(creator_code:org_t)
- Elsevier BV, 1997
- 1997
- English.
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In: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 272:9, s. 5727-5731
- Related links:
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http://www.jbc.org/c...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- Human glutathione transferases (GSTs) were shown to catalyze the reductive glutathione conjugation of aminochrome (2, 3-dihydroindole-5,6-dione). The class Mu enzyme GST M2-2 displayed the highest specific activity (148 micromol/min/mg), whereas GSTs A1-1, A2-2, M1-1, M3-3, and P1-1 had markedly lower activities (<1 micromol/min/mg). The product of the conjugation, with a UV spectrum exhibiting absorption peaks at 277 and 295 nm, was 4-S-glutathionyl-5,6-dihydroxyindoline as determined by NMR spectroscopy. In contrast to reduced forms of aminochrome (leucoaminochrome and o-semiquinone), 4-S-glutathionyl-5, 6-dihydroxyindoline was stable in the presence of molecular oxygen, superoxide radicals, and hydrogen peroxide. However, the strongly oxidizing complex of Mn3+ and pyrophosphate oxidizes 4-S-glutathionyl-5,6-dihydroxyindoline to 4-S-glutathionylaminochrome, a new quinone derivative with an absorption peak at 620 nm. GST M2-2 (and to a lower degree, GST M1-1) prevents the formation of reactive oxygen species linked to one-electron reduction of aminochrome catalyzed by NADPH-cytochrome P450 reductase. The results suggest that the reductive conjugation of aminochrome catalyzed by GSTs, in particular GST M2-2, is an important cellular antioxidant activity preventing the formation of o-semiquinone and thereby the generation of reactive oxygen species.
Subject headings
- MEDICIN OCH HÄLSOVETENSKAP -- Medicinska och farmaceutiska grundvetenskaper -- Farmaceutiska vetenskaper (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Basic Medicine -- Pharmaceutical Sciences (hsv//eng)
Keyword
- NATURAL SCIENCES
- NATURVETENSKAP
- PHARMACY
- FARMACI
Publication and Content Type
- ref (subject category)
- art (subject category)
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