This recombinant Avian infectious bronchitis virus Nucleoprotein (N) gets expressed in mammalian cells and contains the complete 409 amino acid sequence. The protein comes with a C-terminal 6xHis-tag that makes purification and detection much simpler. SDS-PAGE analysis confirms the purity exceeds 85%, which appears suitable for most research applications. This product is for research use only.
The Avian infectious bronchitis virus Nucleoprotein seems to play a central role in the viral life cycle. It's primarily involved in RNA binding and genome packaging - processes that are likely essential for forming the viral ribonucleoprotein complex. This complex represents a key component in viral replication and assembly. Researchers studying viral replication mechanisms or developing strategies against infectious bronchitis virus infections may find understanding this protein's function particularly important.
Potential Applications
Note: The applications listed below are based on what we know about this protein's biological functions, published research, and experience from experts in the field. However, we haven't fully tested all of these applications ourselves yet. We'd recommend running some preliminary tests first to make sure they work for your specific research goals.
The use of a mammalian expression system is advantageous for producing a viral protein intended for mammalian systems, as it is more likely to support proper post-translational modifications and folding environments compared to prokaryotic or lower eukaryotic systems. This increases the probability that the protein could be correctly folded. Nonetheless, this is not a guarantee. While the mammalian expression system is favorable, the correct folding and bioactivity of this specific recombinant IBV N protein batch must be experimentally verified before it can be confidently used in functional studies. It cannot be assumed to be bioactive based on the production information alone.
1. Antibody Development and Validation
This full-length recombinant IBV nucleoprotein has the potential to serve as an immunogen for generating antibodies. The mammalian expression system may support the formation of conformational epitopes. However, the presence of the C-terminal tag could potentially influence the antigenicity of the native C-terminal region. Antibodies generated may primarily recognize linear epitopes, and their ability to bind the native, folded N protein within the virion context requires confirmation. The 85%+ purity is acceptable, but antibodies against contaminants might still be produced. Validation of generated antibodies should include testing against the native virus or proteins from infected cells to confirm specificity and relevance.
2. Protein-Protein Interaction Studies
The His-tagged protein can be used technically in pull-down assays to screen for interacting partners. However, the biological relevance of any identified interactions is entirely dependent on the protein's correct folding and post-translational modifications. If the recombinant N protein is misfolded, it could lead to non-physiological interactions (false positives) or fail to identify true binding partners (false negatives). Crucially, the mammalian cell-expressed protein might lack viral or host-specific factors present during a real infection, which could be essential for authentic interactions. Any interactions discovered must be validated using complementary methods, such as co-immunoprecipitation of native proteins from virus-infected cells.
3. Structural and Biochemical Characterization
The suitability of this protein for high-resolution structural studies (e.g., X-ray crystallography, cryo-EM) is highly contingent on it being properly folded, homogenous, and forming the correct oligomeric state. While mammalian expression may promote native-like folding, the >85% purity by SDS-PAGE does not guarantee monodispersity or the absence of aggregation, which are critical for crystallization or single-particle analysis. The C-terminal tag might also interfere with native structure or oligomerization. Prior to structural studies, thorough biochemical and biophysical characterization (e.g., size-exclusion chromatography with multi-angle light scattering, analytical ultracentrifugation, circular dichroism) is essential to assess folding quality, stability, and oligomeric status.
4. Enzyme-Linked Immunosorbent Assays (ELISA) Development
This recombinant protein can be used as a coating antigen for ELISA development to detect IBV-specific antibodies. The full-length sequence increases the likelihood of presenting a wide range of epitopes. However, the assay's sensitivity and specificity will depend on whether the recombinant protein presents epitopes in their native conformation. If the protein is misfolded, antibodies from infected or vaccinated birds might not bind effectively, leading to reduced sensitivity. Cross-reactivity with antibodies against other coronaviruses is also a possibility that needs evaluation. The performance of any in-house ELISA must be rigorously validated against a gold standard assay and well-characterized positive and negative serum panels.
5. RNA-Binding Studies
The IBV N protein is known to bind viral RNA. This recombinant protein could be used in techniques like EMSA to study RNA-binding properties. However, the functional activity of RNA binding is highly sensitive to correct folding. A misfolded protein may lack binding ability or exhibit non-specific affinity, leading to inaccurate conclusions. Furthermore, post-translational modifications critical for RNA binding in the native virus might not be fully recapitulated in the recombinant system. Binding studies should include appropriate controls, such as a known functional positive control protein, and results should be interpreted with caution unless bioactivity is confirmed.
Final Recommendation & Action Plan
To ensure reliable and meaningful results, it is strongly recommended to first experimentally validate the folding and bioactivity of this recombinant IBV N protein. The action plan should begin with biophysical characterization using size-exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) to assess oligomeric state and monodispersity, and circular dichroism (CD) spectroscopy to analyze secondary structure. This should be followed by functional validation, which could include an immunoassay (e.g., Western blot or ELISA) using confirmed positive antisera from IBV-infected or vaccinated birds to confirm native antigenicity, and if feasible, an RNA-binding assay (e.g., EMSA) with a known IBV RNA sequence to verify biological activity. If the protein passes these validation steps, it can be confidently used for the proposed applications. If validation fails, its use should be restricted to applications less dependent on native conformation, such as antibody production against linear epitopes, with all limitations clearly disclosed in any subsequent research communications .
