title: Analysis of the expression and antioxidant activity of 2-Cys peroxiredoxin protein in Fasciola gigantica.
abstract: 2-Cys peroxiredoxin (Prx) is the main antioxidant enzyme in Fasciola species for detoxifying hydrogen peroxide which is generated from the hosts' immune effector cells and the parasites' own metabolism. In this study, the recombinant Prx protein from Fasciola gigantica (rFgPrx-2) was expressed and purified in a prokaryotic expression system. This recombinant protein with molecular weight of 26 kDa was enzymatically active in reduction of hydrogen peroxide both in presence of thioredoxin and glutathione systems, and also protected the supercoiled plasmid DNA from oxidative damage in metal-catalyzed oxidation (MCO) system in a concentration-dependent manner. By immunoblotting, using antibody against rFgPrx-2 as probe, a native FgPrxs, whose MW at 25 kDa, was detected in all developmental stages of the parasite. Concentrations of native FgPrxs were increasing in all stages reaching highest level in adult stage. The antibody also showed cross reactivities with corresponding proteins in some cattle helminthes. Natural antibody to FgPrxs could be detected in the sera of mice at 3 and 4 weeks after infection with F. gigantica metacercariae. By immunofluorescence, FgPrxs was highly expressed in tegument and tegumental cells, parenchyma, moderately expressed in cecal epithelial cells in early, juvenile and adult worms. Furthermore, FgPrxs was also detected in the female reproductive organs, including eggs, ovary, vitelline cells, and testis, suggesting that FgPrxs might play an essential role in protecting parasite's tissues from free radical attack during their life cycle. Thus, FgPrxs is one potential candidate for drug therapy and vaccine development.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Kant
authors.initials: K
authors.lastname: Sangpairoj
authors.affiliation: Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Narin
authors.initials: N
authors.lastname: Changklungmoa
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Rapeepun
authors.initials: R
authors.lastname: Vanichviriyakit
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand. Electronic address: kulathida.cha@mahidol.ac.th.
authors.forename: Kulathida
authors.initials: K
authors.lastname: Chaithirayanon
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D004249:DNA Damage; D004278:DNA, Superhelical / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005209:Fasciola / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D005978:Glutathione / Q000378:metabolism; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D010084:Oxidation-Reduction; D054464:Peroxiredoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004278:DNA, Superhelical; D015801:Helminth Proteins; D011994:Recombinant Proteins; D013879:Thioredoxins; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D005978:Glutathione
keywords: Antioxidant enzyme; Fasciola gigantica; Peroxiredoxin; Recombinant protein; Tissue distribution