Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis.
The microaerophilic protozoan parasite Giardia intestinalis, causative of one of the most common human intestinal diseases worldwide, infects the mucosa of the proximal small intestine, where it has to cope with O2 and nitric oxide (NO). Elucidating the antioxidant defense system of this pathogen la...
Published in: | PLoS Neglected Tropical Diseases |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Public Library of Science (PLoS)
2014
|
Subjects: | |
Online Access: | https://doi.org/10.1371/journal.pntd.0002631 https://doaj.org/article/1e06c76655574262b473457aeb3e480a |
id |
ftdoajarticles:oai:doaj.org/article:1e06c76655574262b473457aeb3e480a |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:1e06c76655574262b473457aeb3e480a 2023-05-15T15:13:21+02:00 Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. Daniela Mastronicola Micol Falabella Fabrizio Testa Leopoldo Paolo Pucillo Miguel Teixeira Paolo Sarti Lígia M Saraiva Alessandro Giuffrè 2014-01-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0002631 https://doaj.org/article/1e06c76655574262b473457aeb3e480a EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC3886907?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0002631 https://doaj.org/article/1e06c76655574262b473457aeb3e480a PLoS Neglected Tropical Diseases, Vol 8, Iss 1, p e2631 (2014) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2014 ftdoajarticles https://doi.org/10.1371/journal.pntd.0002631 2022-12-30T21:04:27Z The microaerophilic protozoan parasite Giardia intestinalis, causative of one of the most common human intestinal diseases worldwide, infects the mucosa of the proximal small intestine, where it has to cope with O2 and nitric oxide (NO). Elucidating the antioxidant defense system of this pathogen lacking catalase and other conventional antioxidant enzymes is thus important to unveil novel potential drug targets. Enzymes metabolizing O2, NO and superoxide anion (O2 (-•)) have been recently reported for Giardia, but it is yet unknown how the parasite copes with H2O2 and peroxynitrite (ONOO(-)). Giardia encodes two yet uncharacterized 2-cys peroxiredoxins (Prxs), GiPrx1a and GiPrx1b. Peroxiredoxins are peroxidases implicated in virulence and drug resistance in several parasitic protozoa, able to protect from nitroxidative stress and repair oxidatively damaged molecules. GiPrx1a and a truncated form of GiPrx1b (deltaGiPrx1b) were expressed in Escherichia coli, purified and functionally characterized. Both Prxs effectively metabolize H2O2 and alkyl-hydroperoxides (cumyl- and tert-butyl-hydroperoxide) in the presence of NADPH and E. coli thioredoxin reductase/thioredoxin as the reducing system. Stopped-flow experiments show that both proteins in the reduced state react with ONOO(-) rapidly (k = 4×10(5) M(-1) s(-1) and 2×10(5) M(-1) s(-1) at 4°C, for GiPrx1a and deltaGiPrx1b, respectively). Consistent with a protective role against oxidative stress, expression of GiPrx1a (but not deltaGiPrx1b) is induced in parasitic cells exposed to air O2 for 24 h. Based on these results, GiPrx1a and deltaGiPrx1b are suggested to play an important role in the antioxidant defense of Giardia, possibly contributing to pathogenesis. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLoS Neglected Tropical Diseases 8 1 e2631 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Daniela Mastronicola Micol Falabella Fabrizio Testa Leopoldo Paolo Pucillo Miguel Teixeira Paolo Sarti Lígia M Saraiva Alessandro Giuffrè Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
The microaerophilic protozoan parasite Giardia intestinalis, causative of one of the most common human intestinal diseases worldwide, infects the mucosa of the proximal small intestine, where it has to cope with O2 and nitric oxide (NO). Elucidating the antioxidant defense system of this pathogen lacking catalase and other conventional antioxidant enzymes is thus important to unveil novel potential drug targets. Enzymes metabolizing O2, NO and superoxide anion (O2 (-•)) have been recently reported for Giardia, but it is yet unknown how the parasite copes with H2O2 and peroxynitrite (ONOO(-)). Giardia encodes two yet uncharacterized 2-cys peroxiredoxins (Prxs), GiPrx1a and GiPrx1b. Peroxiredoxins are peroxidases implicated in virulence and drug resistance in several parasitic protozoa, able to protect from nitroxidative stress and repair oxidatively damaged molecules. GiPrx1a and a truncated form of GiPrx1b (deltaGiPrx1b) were expressed in Escherichia coli, purified and functionally characterized. Both Prxs effectively metabolize H2O2 and alkyl-hydroperoxides (cumyl- and tert-butyl-hydroperoxide) in the presence of NADPH and E. coli thioredoxin reductase/thioredoxin as the reducing system. Stopped-flow experiments show that both proteins in the reduced state react with ONOO(-) rapidly (k = 4×10(5) M(-1) s(-1) and 2×10(5) M(-1) s(-1) at 4°C, for GiPrx1a and deltaGiPrx1b, respectively). Consistent with a protective role against oxidative stress, expression of GiPrx1a (but not deltaGiPrx1b) is induced in parasitic cells exposed to air O2 for 24 h. Based on these results, GiPrx1a and deltaGiPrx1b are suggested to play an important role in the antioxidant defense of Giardia, possibly contributing to pathogenesis. |
format |
Article in Journal/Newspaper |
author |
Daniela Mastronicola Micol Falabella Fabrizio Testa Leopoldo Paolo Pucillo Miguel Teixeira Paolo Sarti Lígia M Saraiva Alessandro Giuffrè |
author_facet |
Daniela Mastronicola Micol Falabella Fabrizio Testa Leopoldo Paolo Pucillo Miguel Teixeira Paolo Sarti Lígia M Saraiva Alessandro Giuffrè |
author_sort |
Daniela Mastronicola |
title |
Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
title_short |
Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
title_full |
Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
title_fullStr |
Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
title_full_unstemmed |
Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis. |
title_sort |
functional characterization of peroxiredoxins from the human protozoan parasite giardia intestinalis. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2014 |
url |
https://doi.org/10.1371/journal.pntd.0002631 https://doaj.org/article/1e06c76655574262b473457aeb3e480a |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 8, Iss 1, p e2631 (2014) |
op_relation |
http://europepmc.org/articles/PMC3886907?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0002631 https://doaj.org/article/1e06c76655574262b473457aeb3e480a |
op_doi |
https://doi.org/10.1371/journal.pntd.0002631 |
container_title |
PLoS Neglected Tropical Diseases |
container_volume |
8 |
container_issue |
1 |
container_start_page |
e2631 |
_version_ |
1766343916311805952 |