title: CuZn superoxide dismutase activities from Fasciola hepatica.
abstract: The levels of superoxide dismutase (SOD) were determined in detergent-soluble, somatic and excretion-secretion (E-S) preparations from adult Fasciola hepatica using the xanthine oxidase system and visualized in substrate gels. Compared to detergent-soluble and somatic extracts, E-S products showed the highest SOD activity (88.5 U/mg), indicating active release to the medium in which parasites were maintained. SOD specific activity was also detected at high levels in E-S products from 3-week-old and 5-week-old immature migrating flukes (25 and 143 U/mg, respectively). In all preparations except for the somatic extract, the activity was characterized as cyanide-sensitive CuZn SOD. Differences in SOD isoenzyme profiles between the extracts were observed in native polyacrylamide gel electrophoresis: the somatic and detergent-soluble extracts exhibited 1 band of activity while the E-S products from immature and adults flukes contained 2 and 3 migrating bands, respectively. SOD was purified from the detergent-soluble extract and E-S products of adult worms by a combination of ultrafiltration, gel filtration on Sephacryl S-200 HR and ion-exchange chromatography on QAE Sephadex A-50. The SOD from detergent-soluble extract showed, by SDS-PAGE analysis, 1 band of 16 kDa apparent molecular weight. The SOD from E-S products showed 2 bands of 16 and 60 kDa apparent molecular weight. N-terminal sequence analysis of the 16 kDa band from the detergent-soluble preparation showed some similarity with Schistosoma mansoni cytoplasmic SOD. These enzymes may have a potential role in the evasion of the oxidative burst killing mechanism by immune cells.
authors.affiliation: Unidad de Biología Parasitaria, Facultad de Ciencias, Instituto de Higiene, Montevideo, Uruguay.
authors.forename: L
authors.initials: L
authors.lastname: Piacenza
authors.forename: R
authors.initials: R
authors.lastname: Radi
authors.forename: F
authors.initials: F
authors.lastname: Goñi
authors.forename: C
authors.initials: C
authors.lastname: Carmona
mesh_terms: D000367:Age Factors; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005210:Fasciola hepatica / Q000201:enzymology* / Q000254:growth & development; D015801:Helminth Proteins / Q000302:isolation & purification / Q000378:metabolism*; D015151:Immunoblotting; D008297:Male; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000302:isolation & purification / Q000378:metabolism*; D014462:Ultrafiltration
chemical_list: D015801:Helminth Proteins; D013482:Superoxide Dismutase