Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica

The components of the redox metabolism in Entamoeba histolytica have been recently revisited by Arias et al. (Free Radic. Biol. Med. 42:1496-1505; 2007), after the identification and characterization of a thioredoxin-linked system. The present work deals with studies performed for a better understan...

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Autores principales: Arias, Diego G., Carranza, Pedro Gabriel, Luján, Hugo Daniel, Iglesias, Alberto A., Guerrero, Sergio A.
Formato: Artículo
Lenguaje:Español
Publicado: 2008
Materias:
Q Ciencia (General)
Acceso en línea:http://pa.bibdigital.ucc.edu.ar/4807/1/A_Arias.pdf
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Producción Académica Universidad Católica de Córdoba (UCCor) de Universidad Católica de Córdoba
id I38-R144-4807
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spelling I38-R144-48072025-10-24T16:32:57Z http://pa.bibdigital.ucc.edu.ar/4807/ Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica Arias, Diego G. Carranza, Pedro Gabriel Luján, Hugo Daniel Iglesias, Alberto A. Guerrero, Sergio A. Q Ciencia (General) The components of the redox metabolism in Entamoeba histolytica have been recently revisited by Arias et al. (Free Radic. Biol. Med. 42:1496-1505; 2007), after the identification and characterization of a thioredoxin-linked system. The present work deals with studies performed for a better understanding of the localization and identification of different components of the redox machinery present in the parasite. The gene encoding for amoebic thioredoxin 8 was cloned and the recombinant protein typified as having properties similar to those of thioredoxin 41. The ability of these thioredoxins and the specific reductase to assemble a system utilizing NADPH to metabolize hydroperoxides in association with a peroxiredoxin has been kinetically characterized. The peroxiredoxin behaved as a typical 2 cysteine enzyme, exhibiting a ping-pong mechanism with hyperbolic saturation kinetics for thioredoxin 8 (Km = 3.8 μM), thioredoxin 41 (Km = 3.1 μM), and tert-butyl hydroperoxide (Km about 35 μM). Moreover, the tandem system involving thioredoxin reductase and either thioredoxin proved to be operative for reducing low molecular weight disulfides, including putative physiological substrates as cystine and oxidized trypanothione. Thioredoxin reductase and thioredoxin 41 (by association also the functional redox system) have been immunolocalized underlying the plasma membrane in Entamoeba histolytica cells. These findings suggest an important role for the metabolic pathway involving thioredoxin as a redox interchanger, which could be critical for the maintenance and virulence of the parasite when exposed to highly toxic reactive oxygen species. 2008-12-31 info:eu-repo/semantics/article info:eu-repo/semantics/closedAccess application/pdf spa http://pa.bibdigital.ucc.edu.ar/4807/1/A_Arias.pdf Arias, Diego G., Carranza, Pedro Gabriel ORCID: https://orcid.org/0000-0002-1145-3852 <https://orcid.org/0000-0002-1145-3852>, Luján, Hugo Daniel ORCID: https://orcid.org/0000-0002-3797-8315 <https://orcid.org/0000-0002-3797-8315>, Iglesias, Alberto A. and Guerrero, Sergio A. (2008) Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica. Free Radical Biology and Medicine, 45 (1). pp. 32-39. ISSN 08915849 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.freeradbiomed.2008.03.008
institution Universidad Católica de Córdoba
institution_str I-38
repository_str R-144
collection Producción Académica Universidad Católica de Córdoba (UCCor)
language Español
orig_language_str_mv spa
topic Q Ciencia (General)
spellingShingle Q Ciencia (General)
Arias, Diego G.
Carranza, Pedro Gabriel
Luján, Hugo Daniel
Iglesias, Alberto A.
Guerrero, Sergio A.
Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
topic_facet Q Ciencia (General)
description The components of the redox metabolism in Entamoeba histolytica have been recently revisited by Arias et al. (Free Radic. Biol. Med. 42:1496-1505; 2007), after the identification and characterization of a thioredoxin-linked system. The present work deals with studies performed for a better understanding of the localization and identification of different components of the redox machinery present in the parasite. The gene encoding for amoebic thioredoxin 8 was cloned and the recombinant protein typified as having properties similar to those of thioredoxin 41. The ability of these thioredoxins and the specific reductase to assemble a system utilizing NADPH to metabolize hydroperoxides in association with a peroxiredoxin has been kinetically characterized. The peroxiredoxin behaved as a typical 2 cysteine enzyme, exhibiting a ping-pong mechanism with hyperbolic saturation kinetics for thioredoxin 8 (Km = 3.8 μM), thioredoxin 41 (Km = 3.1 μM), and tert-butyl hydroperoxide (Km about 35 μM). Moreover, the tandem system involving thioredoxin reductase and either thioredoxin proved to be operative for reducing low molecular weight disulfides, including putative physiological substrates as cystine and oxidized trypanothione. Thioredoxin reductase and thioredoxin 41 (by association also the functional redox system) have been immunolocalized underlying the plasma membrane in Entamoeba histolytica cells. These findings suggest an important role for the metabolic pathway involving thioredoxin as a redox interchanger, which could be critical for the maintenance and virulence of the parasite when exposed to highly toxic reactive oxygen species.
format Artículo
author Arias, Diego G.
Carranza, Pedro Gabriel
Luján, Hugo Daniel
Iglesias, Alberto A.
Guerrero, Sergio A.
author_facet Arias, Diego G.
Carranza, Pedro Gabriel
Luján, Hugo Daniel
Iglesias, Alberto A.
Guerrero, Sergio A.
author_sort Arias, Diego G.
title Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
title_short Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
title_full Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
title_fullStr Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
title_full_unstemmed Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica
title_sort immunolocalization and enzymatic functional characterization of the thioredoxin system in entamoeba histolytica
publishDate 2008
url http://pa.bibdigital.ucc.edu.ar/4807/1/A_Arias.pdf
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