Norovirus Group-1 Capsid Recombinant
This recombinant norovirus group-1 capsid protein is produced in E. coli and represents the major structural component of the virus. It is derived from the Norwalk virus strain and includes a 6-His tag for purification. The protein is supplied in a solution form and is highly pure, making it suitable for research applications.
Norovirus Group-1 Capsid P-Domain Recombinant
This recombinant Norovirus Group-1 Capsid P-Domain protein, derived from E. coli, represents the Norwalk strain and spans amino acids 225 to 520, resulting in a molecular weight of 30kDa. A 6xHis tag is attached to the protein's N-terminal for purification purposes. This P-domain exhibits a specific structure and contains a region responsible for binding to human cell receptors. Interestingly, when expressed in bacteria, this domain can self-assemble into larger particles, exhibiting enhanced binding capabilities compared to particles formed from the full-length capsid protein.
Norovirus Group-2 Capsid Recombinant
Norovirus Group-2 Capsid P-Domain Recombinant
This recombinant Norovirus Group-2 Capsid P-Domain, derived from E. coli strain VA387, consists of amino acids 225-520 and has a molecular weight of 30kDa. A 6xHis tag is fused to the N-terminal for purification using chromatography. The P-domain (225-520 a.a.) forms a P1-P2-P1 structure and possesses a receptor-binding region for recognizing human histo-blood group antigens (HBGAs). When expressed in bacteria, the P-domain can spontaneously form a P dimer and a P particle composed of 12 P dimers. This P-particle exhibits an enhanced binding affinity for HBGAs compared to the virus-like particle (VLP) formed by the full-length capsid.
Norovirus, also known as the Norwalk virus, is a genus of viruses within the family Caliciviridae. It is a non-enveloped, single-stranded RNA virus that is a leading cause of gastroenteritis worldwide . Noroviruses are classified into seven genogroups (GI-GVII), with genogroups I, II, and IV primarily infecting humans .
Key Biological Properties: Noroviruses are small, non-enveloped viruses with a diameter of 27-32 nm. They have a buoyant density of 1.33 to 1.41 g/cm³ in cesium chloride . The genome is approximately 7.4 to 7.7 kb in length and consists of three open reading frames (ORFs) .
Expression Patterns and Tissue Distribution: Noroviruses primarily infect the epithelial cells of the small intestine. They are highly resistant to environmental conditions, including freezing and heating up to 60°C .
Primary Biological Functions: Noroviruses are responsible for causing acute gastroenteritis, characterized by symptoms such as vomiting, diarrhea, and stomach pain . They play a significant role in immune responses by evoking limited immunity, which allows for repeated infections throughout a person’s lifetime .
Role in Immune Responses and Pathogen Recognition: Noroviruses interact with the host’s immune system, often evading detection and causing infection. They are recognized by the host’s immune system through pathogen-associated molecular patterns (PAMPs), which trigger immune responses .
Mechanisms with Other Molecules and Cells: Noroviruses bind to histo-blood group antigens (HBGAs) on the surface of host cells, facilitating entry and infection . The viral protein VPg interacts with host ribosomes to initiate the translation of viral RNA .
Binding Partners and Downstream Signaling Cascades: The interaction between norovirus VPg and host ribosomes is crucial for viral replication. This interaction recruits ribosomes to the viral RNA, enabling the synthesis of viral proteins .
Regulatory Mechanisms Controlling Expression and Activity: Norovirus replication involves the production of subgenomic RNA, which is used as an indicator of active viral genome replication . The virus also regulates the host’s innate immune response by delaying the upregulation of immune-related genes .
Transcriptional Regulation and Post-Translational Modifications: Noroviruses employ various strategies to modulate host cell functions, including the use of viral proteins to interfere with host transcriptional machinery and post-translational modifications .
Biomedical Research: Noroviruses are studied extensively to understand viral pathogenesis and immune evasion mechanisms. Research on noroviruses has led to insights into viral replication and host interactions .
Diagnostic Tools and Therapeutic Strategies: Diagnostic tools for norovirus include molecular techniques such as RT-PCR to detect viral RNA. Therapeutic strategies are primarily supportive, focusing on hydration and symptom management . Vaccine development is ongoing, with several candidates in clinical trials .
Role Throughout the Life Cycle: Noroviruses have a prolonged infection period, with an incubation period of 12-48 hours . They infect host cells by binding to specific receptors, hijacking the host’s cellular machinery to replicate and produce new viral particles . The virus is shed in large quantities in feces and vomit, facilitating transmission .