HEV ORF2 (403-461 a.a.)
Description
Introduction to HEV ORF2 (403–461 a.a.)
The HEV ORF2 (403–461 a.a.) region represents a critical segment of the Hepatitis E virus (HEV) capsid protein, encoded by open reading frame 2 (ORF2). This 59-amino acid sequence is part of the larger ORF2 protein (660 a.a.), which forms the viral capsid and elicits strong immune responses during HEV infection . The 403–461 region is located within domain 4 of ORF2, a highly immunogenic region identified as a key target for diagnostic assays and antibody recognition .
ORF2 Domain Architecture
ORF2 is organized into six antigenic domains, with domain 4 spanning amino acids 381–504 . This region is conformation-dependent and contains multiple epitopes, making it a critical target for antibody-mediated immune responses .
Table 1: Antigenic Domains of HEV ORF2 Protein
The 403–461 region lies within domain 4, which is notable for its high sequence conservation across HEV genotypes, despite some strain-specific variability .
Immunogenicity and Diagnostic Utility
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Antigenic Reactivity: The 403–461 region is part of domain 4, which contains 5+ epitopes identified via synthetic peptides. These epitopes are efficiently modeled with 30-mer peptides and react with >70% of anti-HEV sera .
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Diagnostic Applications: The recombinant protein is used in ELISA and Western blot assays to detect HEV-specific IgG and IgM antibodies. It differentiates HEV-positive sera from negatives with high specificity .
Immune Modulation
ORF2’s capsid protein (including domain 4) interacts with host immune pathways, such as TBK1, to suppress interferon (IFN) production and NF-κB signaling . This immune evasion mechanism allows HEV to persist despite host antiviral responses .
Phosphorylation and Post-Translational Modifications
While the 403–461 region lacks detailed phosphorylation data, ORF2 contains numerous phosphorylation sites (e.g., Ser, Thr, Tyr residues), often located in disordered regions. These modifications may regulate viral replication and host-cell interactions .
Current Diagnostic Use
The HEV ORF2 (403–461 a.a.) recombinant protein is critical for:
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Serological Testing: Detecting anti-HEV antibodies in ELISA assays .
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Vaccine Development: Studying immune responses to domain 4 epitopes .
Therapeutic Potential
Product Specs
Product Science Overview
Hepatitis E virus (HEV) is a zoonotic pathogen responsible for causing hepatitis in both humans and animals. It is a significant cause of acute hepatitis outbreaks worldwide. HEV is a single-stranded, positive-sense RNA virus with a genome length of approximately 7.2 kb. The genome encodes three well-defined open reading frames (ORFs): ORF1, ORF2, and ORF3 .
The recombinant ORF2 protein fragment, spanning amino acids 403 to 461, is a specific segment of the ORF2 protein. This fragment has been expressed in various systems, including Escherichia coli, to facilitate research and diagnostic applications. The recombinant protein is often used in enzyme-linked immunosorbent assays (ELISA) and Western blot (WB) techniques due to its high purity and reactivity with HEV-positive serum .
The recombinant ORF2 (403-461 a.a.) protein is typically expressed in E. coli, a common host for producing recombinant proteins. The expression system ensures high yields and allows for the purification of the protein to greater than 95% purity. The purified protein is tag-free, making it suitable for various applications without interference from fusion tags .
The recombinant ORF2 (403-461 a.a.) protein is widely used in research and diagnostic settings. Its primary applications include:
- ELISA: The protein is used as an antigen in ELISA to detect antibodies against HEV in serum samples.
- Western Blot: It serves as a target protein in Western blot assays to identify HEV-specific antibodies.
- Vaccine Development: The ORF2 protein is a potential candidate for developing vaccines against HEV due to its immunogenic properties .
