The Hepatitis C Virus (HCV) NS3/4A serine protease is essential for viral replication and the formation of infectious viral particles, and thus has been considered as one of the most attractive targets for anti-HCV therapy. Due to poor fidelity of viral reverse transcriptase and RNA-dependent RNA polymerase, drug resistant mutations emerge rapidly against protease inhibitors. The mutant A156V has been identified to confer the cross-resistance to two potent protease inhibitors, VX-950 and BILN 2061.
The recombinant HCV NS3/4A protease mutant A156V is derived from its wild type (NCBI Accession: CAB46913) with a substitution of Ala156 with Val. It is a 217 amino acid fusion protein with NS3 protease domain and a fragment of the NS4A protein fused to its N-terminus.