This recombinant Avian infectious bronchitis virus Spike glycoprotein (S) is produced in an E.coli expression system, covering the amino acid region 318-538. The protein includes a C-terminal 6xHis tag for easier purification and detection. SDS-PAGE analysis shows the product maintains purity greater than 85%, which appears to provide reliable quality for research applications.
The Spike glycoprotein (S) of Avian infectious bronchitis virus seems to play a crucial role in viral entry into host cells by mediating attachment and fusion. This protein represents a key component of the viral envelope. Scientists commonly study it in virology research for its involvement in virus-host interactions and its potential as a target for vaccine development.
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 IBV Spike protein is naturally glycosylated, and its correct folding and disulfide bond formation are crucial for forming its native trimeric structure and achieving biological function, such as receptor binding. The E. coli system lacks the cellular machinery for eukaryotic post-translational modifications, particularly glycosylation. Furthermore, the reducing environment of the bacterial cytoplasm is not conducive to the correct formation of the complex disulfide bonds that are essential for the structure of viral glycoproteins. While the protein fragment might be soluble, it will almost certainly not adopt the native conformation found on the virus.
1. Antibody Development and Characterization
This recombinant IBV spike protein fragment may serve as an immunogen for generating antibodies, particularly those targeting linear epitopes within the 318-538aa region. The C-terminal His-tag facilitates purification. However, because the protein is likely misfolded and non-glycosylated, antibodies generated against it may fail to recognize the native, glycosylated, and correctly folded Spike protein on the viral surface. This severely limits the utility of such antibodies in applications like virus neutralization or immunofluorescence that depend on recognition of the native protein conformation.
2. Structural and Biochemical Characterization
This protein fragment is unsuitable for determining the native structure of the IBV Spike region. Techniques like circular dichroism might reveal a spectrum, but the data would represent the misfolded state in E. coli, not the biologically relevant structure. It can be used for basic biochemical analyses like determining its amino acid sequence or mass. However, attempts to map post-translational modifications would be futile, as E. coli does not glycosylate proteins, and the fragment will lack the modifications present in the authentic virus.
Final Recommendation & Action Plan
Given the high likelihood of misfolding, the primary recommendation is to restrict the use of this protein to applications that do not depend on native conformation, such as generating antibodies targeting linear epitopes or as a negative control in folding studies. For any application requiring a functional Spike protein (especially interaction studies, structural work, or vaccine research), it is strongly advised to seek an alternative recombinant protein expressed in a eukaryotic system (e.g., mammalian, insect, or yeast cells) that can support proper glycosylation and folding, as demonstrated in published research on IBV.
