Recombinant Severe acute respiratory syndrome coronavirus 2 Spike glycoprotein (S) (K417N) is expressed in mammalian cells and comes with a C-terminal 10xHis tag for straightforward purification. This product contains the amino acid region 319-541 with the K417N mutation, supplied as a partial protein. SDS-PAGE analysis confirms purity levels above 90%, while endotoxin levels remain below 1.0 EU/ug, making it suitable for sensitive research applications.
The Spike glycoprotein (S) of SARS-CoV-2 appears to play a central role in how the virus enters host cells by helping with attachment and fusion processes. It's become a major focus for researchers studying viral pathogenesis and vaccine development. Understanding how the Spike protein works structurally and functionally may be essential for creating effective therapeutic strategies against COVID-19.
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 protein is expressed in a mammalian system (e.g., CHO or HEK293 cells), which is highly supportive of native-like folding and post-translational modifications (e.g., glycosylation)—critical for the SARS-CoV-2 Spike Receptor Binding Domain (RBD, 319–541 aa) to adopt a functional conformation. The C-terminal 10xHis-tag is minimally disruptive to structure, and the K417N mutation (a common variant change in Omicron) is localized to the RBD, reducing the risk of global misfolding. However, no direct validation of folding (e.g., circular dichroism for secondary structure, thermal shift assays for stability) or bioactivity (e.g., ACE2 binding affinity, neutralization potential) is provided. While mammalian expression strongly suggests correct RBD folding, the impact of the K417N mutation on these properties remains untested—bioactivity is probable but not confirmed.
1. Antibody Development and Characterization Studies
This K417N-mutant RBD fragment can serve as an immunogen or screening antigen for variant-targeted monoclonal antibodies. The C-terminal His-tag enables purification and immobilization in ELISA, but cross-reactivity with wild-type Spike must be validated via comparative ELISA/neutralization assays. High purity supports immunization, but endotoxin levels (not explicitly stated) should be confirmed to avoid artifacts in animal studies.
2. Protein-Protein Interaction Studies
The RBD (319–541 aa) is the primary ACE2-binding region, making this protein useful for studying variant-specific interactions. Pull-down assays with the His-tag can identify interactors—but RBD’s main function is ACE2 binding, so "beyond ACE2" interactions are speculative. Mutation-driven changes in binding kinetics must be quantified via SPR/BLI and compared to wild-type.
3. Structural and Biophysical Characterization
The mutant RBD fragment is suitable for structural studies (e.g., CD spectroscopy, DLS, or cryo-EM). Mammalian glycosylation supports native-like structure—but the C-terminal His-tag may interfere with crystallization; tag removal (via protease cleavage) may improve resolution. Thermal shift assays can validate mutation-induced stability changes.
4. Vaccine Research and Immunogenicity Studies
This mutant RBD can evaluate preclinical immune responses to the K417N variant. The His-tag aids quantification—but cross-reactivity to wild-type RBD and variant-specific neutralization must be tested via in vitro immunoassays. High purity and low endotoxin support controlled studies, but results require comparison to wild-type to define mutation effects on immunogenicity.
Final Recommendation & Action Plan
This mammalian-expressed K417N-mutant RBD (319–541 aa) has strong potential for RBD-focused applications due to its native-like folding and glycosylation, but rigorous validation is essential first, to confirm RBD conformation (CD spectroscopy) and ACE2 binding affinity (SPR); second, test antibody cross-reactivity and neutralization against wild-type vs. mutant; third, optimize structural studies (e.g., tag removal for crystallization). For immunogenicity, include wild-type controls to assess mutation impacts. If validation passes, use the protein for its intended fragment-specific goals (mutation studies, antibody screening)—always contextualizing results with wild-type comparisons. If folding/binding fails, revisit expression conditions or use a glycosylation-optimized mammalian system (e.g., CHO-K1 with glycoengineering).
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