Expression of the CHV or HCV NS3/4A protease resulted in nearly complete cleavage of the lambda cI repressor with either MAVS (A) or TRIF (B) cleavage site.

Expression of the protease was induced with IPTG for 3 h. The Western blot proved that the lambda cI repressor with either MAVS or TRIF cleavage site was not cleaved by NS3/4A proteases that included a substitution in catalytic residue S139. Similarly, a control mutant TRIF target site (Fig. 1) was not cleaved by wild-type NS3/4A proteases. The HCV 1 NS3/4A protease was also tested without IPTG.