Translator Disclaimer
1 October 2000 MOLECULAR AND ENZYMATIC CHARACTERIZATION OF SCHISTOSOMA MANSONI THIOREDOXIN PEROXIDASE
Author Affiliations +
Abstract

The ability of Schistosoma mansoni to escape oxidative damage from immune system-generated reactive oxygen intermediates has been extensively documented. The limiting step in the parasite's detoxification process appears to be at the level of hydrogen peroxide neutralization. In the present study, the possible role of a novel class of antioxidant enzymes, thioredoxin peroxidase (TPx), in hydrogen peroxide neutralization by schistosomes was investigated. An expressed sequence tag was characterized from the Schistosoma Genome Initiative with high similarity to TPx from other organisms. The gene encodes a polypeptide containing 2 conserved active-site cysteines and flanking amino acids, and 60–70% identity with previously characterized TPx proteins. Recombinant schistosome TPx was enzymatically active and found to have thioredoxin-dependent hydrogen peroxide reducing activity of 4500 nmol hydrogen peroxide/min/mg protein. Native TPx activity was determined to be 48.1 nmol hydrogen peroxide/min/mg protein in adult worm homogenates compared with 46.9 for glutathione peroxidase. TPx activity was precipitated from adult worm homogenates with antibodies prepared against the recombinant protein. Western blotting with antibodies made against recombinant protein showed that TPx was expressed in both male and female adult worms. This is the first demonstration of a TPx activity in schistosomes and our results suggest that TPx plays a significant role in schistosome–host interactions.

Mark A. Kwatia, Douglas J. Botkin, and David L. Williams "MOLECULAR AND ENZYMATIC CHARACTERIZATION OF SCHISTOSOMA MANSONI THIOREDOXIN PEROXIDASE," Journal of Parasitology 86(5), 908-915, (1 October 2000). https://doi.org/10.1645/0022-3395(2000)086[0908:MAECOS]2.0.CO;2
Received: 20 October 1999; Accepted: 1 February 2000; Published: 1 October 2000
JOURNAL ARTICLE
8 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top