Purification and characterization of glutathione reductase (E.C. 1.8.1.7) from bovine filarial worms Setaria cervi

Antioxidant enzymes are the parasite’s premier resource to defend themselves against reactive oxygen species generated by macrophages, neutrophils and eosinophils of the host. These enzymes may be particularly important for parasites involved in chronic infections, such as parasitic helminths. Glutathione (GSH) and glutathione reductase (GR) are parts of the GSH redox cycle, which protects cells against damage by oxidants. Both GSH and GR are present in significant amounts in Setaria cervi female worms. GR has a central role in glutathione metabolism and as such is a potential target for chemotherapy. The aim of the work was to purify and characterize GR from S. cervi and to compare the properties of the helminth enzyme with its mammalian counterpart. GR was purified from filarial parasites S. cervi and preliminary steady state kinetics was performed. The purified protein was observed to be a dimer of 55 kDa subunit as evident from SDS-PAGE analysis. Kinetic studies revealed significant differences in the properties of S. cervi GR from its mammalian counterpart which may be exploited in chemotherapy of filariasis. Filarial GR is thus proposed as a potential drug target.