HCV NS4 (1916-1947 a.a.)
Description
Introduction to HCV NS4 (1916-1947 a.a.)
HCV NS4 (1916-1947 a.a.) refers to a 32-amino acid peptide spanning residues 1916 to 1947 within the NS4 protein of the hepatitis C virus (HCV). This region lies within the nonstructural polyprotein of HCV, which is processed into NS4A and NS4B during viral replication . While NS4A serves as a cofactor for the NS3 protease , the NS4 protein itself contains epitopes critical for host immune recognition and viral replication.
Immunological Significance
The 1916-1947 a.a. region is a dominant target for humoral immune responses in HCV infection. Studies have shown:
| Disease Group | Antibody Prevalence |
|---|---|
| Autoimmune Hepatitis (AIH) | 64% |
| Chronic Hepatitis C (CHC) | 51% |
| Mixed Cryoglobulinemia (MC) | 22% |
Research Applications and Experimental Use
The recombinant HCV NS4 (1916-1947 a.a.) peptide is commercially available for research purposes, primarily used in:
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Serological Assays: Detecting anti-NS4 antibodies in clinical samples .
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Immunogenicity Studies: Investigating epitope-specific B-cell responses .
Example Use Case:
In a study analyzing HCV-specific antibodies, synthetic peptides corresponding to 1916-1947 a.a. were employed in ELISA assays to differentiate between HCV-related disorders and unrelated conditions .
Challenges and Gaps in Current Research
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Limited Functional Data: While the region is immunogenic, its direct role in viral replication or pathogenesis remains unclear.
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Sequence Overlap with NS4A: Studies often conflate NS4 and NS4A, complicating interpretation of its specific functions .
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Resistance and Therapeutic Targets: Unlike NS3/4A protease inhibitors (e.g., boceprevir, telaprevir), the 1916-1947 a.a. region is not a primary target for direct-acting antivirals (DAAs) .
Product Specs
Product Science Overview
Hepatitis C Virus (HCV) is a positive, single-stranded RNA virus belonging to the Flaviviridae family. The virus is responsible for a significant proportion of chronic viral hepatitis cases worldwide, which can progress to severe liver diseases such as cirrhosis and hepatocellular carcinoma. The HCV genome encodes a single polyprotein of approximately 3,000 amino acids, which is processed into structural and nonstructural proteins by host and viral proteases.
The nonstructural protein 4 (NS4) of HCV is a crucial component of the viral replication complex. It is divided into two segments: NS4A and NS4B. NS4A acts as a cofactor for the NS3 serine protease, stabilizing its folding and facilitating its enzymatic activity. NS4B, on the other hand, is a relatively hydrophobic protein that plays a role in the formation of the membranous web, a structure essential for viral RNA replication.
The recombinant NS4 protein fragment, spanning amino acids 1916 to 1947, is expressed in Escherichia coli and is used extensively in research. This fragment is part of the larger NS4 protein and retains significant antigenic properties, making it valuable for various immunological assays.
Recombinant NS4 (1916-1947 a.a.) is utilized in several applications, including:
- SDS-PAGE: For analyzing protein purity and molecular weight.
- ELISA: For detecting antibodies against HCV in serum samples.
- Western Blotting: For identifying specific proteins in a sample.
- Flow Cytometry: For analyzing protein expression on the cell surface.
The recombinant NS4 protein fragment is crucial for studying the antigenic heterogeneity of HCV proteins. It helps in understanding the immune response against HCV and in developing diagnostic assays. The high purity (>95%) of the recombinant protein ensures reliable and reproducible results in various experimental setups .
