Differential effects of flavonols on inactivation of alpha1-antitrypsin induced by hypohalous acids and the myeloperoxidase-hydrogen peroxide-halide system.
Arch Biochem Biophys
; 459(1): 137-42, 2007 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-17141727
ABSTRACT
Alpha1-antitrypsin is well known for its ability to inhibit human neutrophil elastase. Pretreatment of alpha1-antitrypsin with hypohalous acids HOCl and HOBr as well as with the myeloperoxidase-hydrogen peroxide-chloride (or bromide) system inactivated this proteinase. The flavonols rutin, quercetin, myricetin, and kaempferol inhibited the inactivation of alpha1-antitrypsin by HOCl and HOBr with rutin having the most pronounced effect. In contrast, these flavonols did not remove the proteinase inactivation by the myeloperoxidase-hydrogen peroxide-halide system. Taurine did not protect against the inactivation of alpha1-antitrypsin by HOCl, HOBr, or the myeloperoxidase-hydrogen peroxide-halide system, while methionine was efficient in all systems. A close association between myeloperoxidase and alpha1-antitrypsin was revealed by native gel electrophoresis and in-gel peroxidase staining. In addition, alpha1-antitrypsin binds to the myeloperoxidase components transferred after SDS-PAGE on a blotting membrane. With this complex formation, myeloperoxidase overcomes the natural antioxidative protective system of plasma and prevents the inactivation of alpha1-antitrypsin.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bromatos
/
Alfa 1-Antitripsina
/
Ácido Hipocloroso
/
Peroxidase
/
Flavonóis
/
Halogênios
/
Peróxido de Hidrogênio
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article