We determined three crystal structures of Schistosoma mansoni cathepsin B1 (SmCB1) in complex with peptidomimetic inhibitors. A panel of vinyl sulfone inhibitors was screened in vitro with SmCB1 and in a schistosomula assay; severity of phenotype induced in the parasite correlated with enzyme inhibition.
Substrate specificity of SmCB1 was analyzed using synthetic peptides and the natural substrate, hemoglobin.