Thioredoxin peroxidase

The effectors of the mammalian host immune attack against filaria include reactive oxygen intermediates. Filarial nematodes express glutathione peroxidase, thioredoxin peroxidase and superoxide dismutase at their surface - enzymes believed to protect the nematode from this attack (Selkirk et al., 1998). A bacterial catalase gene has been identified that most probably derives from the endosymbiont genome (Henkle-Duhrsen et al., 1998) this enzyme may contribute with other enzymes to the protection of both Wolbachia and its nematode host from oxygen radicals. 

Lu, W.H., Egerton, G.L., Bianco, A.E. and Williams, S.A. (1998) Thioredoxin peroxidase from Onchocerca volvulus a major hydrogen peroxide detoxifying enzyme in filarial parasites. Molecular and Biochemical Parasitology 91, 221-235. 

RNA binding motif protein 8A Reticulocalbin Thioredoxin peroxidase Transgelin (SM22-alpha) Transmembrane protein 4 Tropomyosin alpha 4 chain Tubulin alpha-1 chain Tubulin beta-5 chain Ubiquitin C-terminal esterase Tropomyosin isoform 1... 

Williams, D.L., Asahi, H., Botkin, D.J. and Stadecker, M.J. (2001) Schistosome infection stimulates host CD4(+)T helper cell and B-cell responses againsta novel egg antigen, thioredoxin peroxidase. Infection and Immunity 69, 1 1 34-11 41. 

Characterization of the enzymatic activity of the parasite and snail recombinant TPx are in progress, and the recombinant snail enzyme BgTPx has been found to be enzymatically active in an in vitro assay (Sayed and Williams, 2004). It remains to be seen whether the results obtained showing the transcript corresponding to BgTPx to be upregulated in parasite-exposed snails, compared to uninfected controls, correlates with enhanced thioredoxin peroxidase activity in infected snails. 

Fig. 11.1. Multiple sequence alignment of the deduced amino acid sequence of thioredoxin peroxidase 1 (Peroxiredoxin 2, TSA, natural killer cell enhancing factor B) from the snail host B. glabrata clone BgTPx (GenBank Accession AAK26236), the parasites S. mansoni (GenBank Accession ...

P. falciparum has been shown to contain a thioredoxin redox system— thioredoxin reductase (TrxR), thioredoxin and thioredoxin peroxidases (Nickel et ah, 2006). P. falciparum thioredoxin reductase is similar to GR in that it is homodimeric, NADPH dependent and binds one FAD per subunit. TrxR appears to be essential to parasite survival as knockout of the gene is lethal (Krnajski et ah, 2002). In a screen of 350,000 compounds, several unsaturated Mannich bases were identified as potential inhibitors of TrxR. The screen, as well as structure-activity relationship studies, resulted in the development of the first specific PfTrxR inhibitors (Andricopulo et ah, 2006 Davioud-Charvet et ah, 2003). 

P. falciparum possesses four peroxiredoxins (Prx) (reviewed in Becker et ah, 2005 Deponte et ah, 2007 Kawazu et ah, 2007). Three of them, thioredoxin peroxidase 1 (Tpxl), 1-Cys-Prx and 2-Cys-Prx, are cytosolic whereas the fourth protein, thioredoxin peroxidase 2 (TPx2), has a mitochondrial targeting sequence that was experimentally shown to be functional and... 

Donnelly S, O Neill SM, Sekiya M. Thioredoxin peroxidase secreted by Fasciola hepatica induces the alternative activation of macrophages. Infect Immun 2005 73 166-173. 

Chandrashekar R, Curtis KC, Lu W et al. Molecular cloning of an enzymatically active thioredoxin peroxidase from Onchocerca volvulus. Mol Biochem Parasitol 1998 93 309-312. 

Kwatia MA, Botkin DJ, Williams DL. Molecular and enzymatic characterization of Schistosoma mansoni thioredoxin peroxidase. J Parasitol 2000 86 908-915. 

Margutti P, Ortona , Delunardo F et al. Thioredoxin peroxidase from Echinococcus granulosus a candidate to extend the antigenic panel for the immunodiagnosis of human cystic echinococcosis. Diagn Microbiol Infect Dis 2008 60 279-285. 

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