Cruzain (Cruzipain, GP57/51) is a member of the papain C1 family of cystein proteinases. The T. cruzi enzyme consists of a catalytic moiety with high identity to cathepsins S and L. and a particular C-terminal domain (C-T) which is absent in all other CPs of the C1 described families.
Irreversible inhibitors of cruzipain (peptidyl diazomethyl ketones, peptidyl fluoromethylketones, peptidyl vinyl sulphones) are able to block the differentiation steps in the parasite’s life cycle, and effectively kill the organism. Thus, cruzipain is an attractive potential target for the development of new drugs against Chagas disease.