• Species: Human Hepatitis C Virus
• Expression Host: E.coli
• Tag: His-tag
• Purity: 95%
• Molecular Weight: 22.7 kDa.
• Gene Accession Number: X61596.

Purification and Quality Control
The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns.
The purified HCV-NS4A/NS3-1b Protease (Strain HC-J4) is greater than 95% homogeneous based on SDS-PAGE analysis.

Unit Definition (Activity)
1 unit equals 1 nanogram of purified protein. 20-200ng is sufficient for an in vitro protease assay.

Applications
Research Use Only. HCV NS3/4A can be applied in in vitro assay development and screening of protease inhibitors.

Formulation and Storage
The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles.

BackgroundPersistent infection with hepatitis C virus (HCV) is a common cause of chronic liver disease, including chronic hepatitis, cirrhosis, and hepatocellular carcinoma (1). HCV is an enveloped, single-stranded RNA virus with a 9.6-kb positive-polarity genome, which encodes a polyprotein precursor of about 3,000 amino acids. The HCV polyprotein is proteolytically processed by cellular and HCV proteases into at least 10 distinct products (reviewed in 2).

NS3 serine protease and helicase as well as NS5B RNA-dependent RNA polymerase are believed to be components of a replication complex responsible for viral RNA replication and have been shown to be essential for the HCV replication in chimpanzees (3). These HCV enzymes have been the major targets for the development of HCV-specific therapeutics during the past decade (for a review, see Ref. 4).

The HCV NS3/4A protease is responsible for cleavage at four sites within the HCV polyprotein to generate the N termini of the NS4A, NS4B, NS5A, and NS5B proteins (5-7). It has been shown that the central region (amino acids 21–30) of the 54-residue NS4A protein is essential and sufficient for the enhancement of proteolytic activity of the NS3 serine protease (8, 9). In recent phase I trials, a 2–3-log reduction of HCV viral load was observed after a 2-day treatment with a serine protease inhibitor, which provided the first proof-of-concept evidence that HCV NS3/4A protease inhibitors could be a new therapeutic option for hepatitis C patients (10).

Image of SDS-PAGE