Profiling selectivity of chagasin mutants towards cysteine proteases cruzain or cathepsin L through molecular dynamics simulations.

Chagasin, an endogenous cysteine protease inhibitor from , can control the activity of the parasitic cruzain and its homologous human cathepsin L. While chagasin inhibits both enzymes with similar potency, mutations have different effects on binding to these enzymes. Mutants T31A and T31A/T32A bind well to cathepsin L, but their affinity for cruzain drops ∼40 to 140-fold.