Isolation and Characterization of Cathepsin-L1 Protease From Fasciola hepatica Excretory-Secretory Products for Serodiagnosis of Human Fasciolosis

The major antigens secreted by the parasite Fasciola hepatica are cathepsin-L cysteine proteases. These enzymes can be isolated from the parasite excretory-secretory products in sufficient quantities for use as an antigen for the serodiagnosis of human fasciolosis. The methods illustrated in this chapter will explain the isolation of cysteine proteases from F. hepatica excretory-secretory products by gel filtration and anion exchange chromatography, and their subsequent characterization and employment in an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-fasciola antibodies in the serum of infected humans.