Cathepsin L1, the major protease involved in liver fluke (Fasciola hepatica) virulence: propetide cleavage sites and autoactivation of the zymogen secreted from gastrodermal cells.

The secretion and activation of the major cathepsin L1 cysteine protease involved in the virulence of the helminth pathogen Fasciola hepatica was investigated. Only the fully processed and active mature enzyme can be detected in medium in which adult F. hepatica are cultured.