FIG. 7.

Cysteine protease inhibitory activity of CcBV cystatin 1. Various concentrations of cystatin 1 were incubated with papain (1 nM) (A) or human cathepsin B (1.8 nM), cathepsin L (0.6 nM), or Sarcophaga cathepsin B (approximately 1 nM) (B). The relative activity of each cysteine protease was determined in presence of the recombinant cystatin 1. Incubation of each protease with the substrate and without addition of cystatin 1 corresponded to 100% activity of the enzymes.