Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Más filtros

Bases de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Microbiol Biotechnol ; 20(1): 88-93, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20134238

RESUMEN

Superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) play crucial roles in balancing the production and decomposition of reactive oxygen species (ROS) in living organisms. These enzymes act cooperatively and synergistically to scavenge ROS. In order to imitate the synergism of these enzymes, we designed and synthesized a novel 32-mer peptide (32P) on the basis of the previous 15-mer peptide with GPX activity and a 17-mer peptide with SOD activity. Upon the selenation and chelation of copper, the 32-mer peptide is converted to a new Se- and Cu-containing 32-mer peptide (Se-Cu-32P) and displays both SOD and GPX activities and its kinetics was studied. Moreover, the novel peptide was demonstrated to be able to better protect vero cells from the injury induced by xanthine oxidase (XOD)/xanthine/Fe2+ damage system than its parents. Thus, this bifunctional enzyme imitated the synergism of SOD and GPX and could be a better candidate of therapeutic medicine.


Asunto(s)
Glutatión Peroxidasa/química , Péptidos/química , Superóxido Dismutasa/química , Animales , Chlorocebus aethiops , Cobre/química , Glutatión Peroxidasa/síntesis química , Glutatión Peroxidasa/farmacología , Cinética , Estrés Oxidativo/efectos de los fármacos , Péptidos/síntesis química , Péptidos/farmacología , Selenio/química , Superóxido Dismutasa/síntesis química , Superóxido Dismutasa/farmacología , Células Vero
2.
FEBS J ; 274(15): 3846-54, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17617230

RESUMEN

A 6A,6A'-dicyclohexylamine-6B,6B'-diselenide-bis-beta-cyclodextrin (6-CySeCD) was designed and synthesized to imitate the antioxidant enzyme glutathione peroxidase (GPX). In this novel GPX model, beta-cyclodextrin provided a hydrophobic environment for substrate binding within its cavity, and a cyclohexylamine group was incorporated into cyclodextrin in proximity to the catalytic selenium in order to increase the stability of the nucleophilic intermediate selenolate. 6-CySeCD exhibits better GPX activity than 6,6'-diselenide-bis-cyclodextrin (6-SeCD) and 2-phenyl-1,2-benzoisoselenazol-3(2H)-one (Ebselen) in the reduction of H(2)O(2), tert-butyl hydroperoxide and cumenyl hydroperoxide by glutathione, respectively. A ping-pong mechanism was observed in steady-state kinetic studies on 6-CySeCD-catalyzed reactions. The enzymatic properties showed that there are two major factors for improving the catalytic efficiency of GPX mimics. First, the substrate-binding site should match the size and shape of the substrate and second, incorporation of an imido-group increases the stability of selenolate in the catalytic cycle. More efficient antioxidant ability compared with 6-SeCD and Ebselen was also seen in the ferrous sulfate/ascorbate-induced mitochondria damage system, and this implies its prospective therapeutic application.


Asunto(s)
Cloro/química , Ciclodextrinas/química , Ciclodextrinas/metabolismo , Glutatión Peroxidasa/metabolismo , Compuestos de Organoselenio/química , Compuestos de Organoselenio/metabolismo , Selenio/química , beta-Ciclodextrinas/química , beta-Ciclodextrinas/metabolismo , Animales , Catálisis , Bovinos , Ciclodextrinas/síntesis química , Cinética , Mitocondrias Cardíacas/metabolismo , Estructura Molecular , Compuestos de Organoselenio/síntesis química , Estrés Oxidativo , beta-Ciclodextrinas/síntesis química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA