Recombinant Severe acute respiratory syndrome coronavirus 2 Spike glycoprotein (S) (E484K), partial (Active)

Recombinant Severe acute respiratory syndrome coronavirus 2 Spike glycoprotein (S) (E484K) is produced using a mammalian cell expression system, which appears to ensure proper folding and post-translational modifications. This partial protein spans amino acids 319-541 with an E484K mutation and includes a C-terminal mFc tag that makes detection and purification more straightforward. The product shows over 90% purity as confirmed by SDS-PAGE while maintaining a low endotoxin level of less than 1.0 EU/µg. Functional ELISA assays have validated its biological activity, demonstrating effective binding to human ACE2 and Biotin-S antibodies.

SARS-CoV-2's Spike glycoprotein (S) plays what may be the most crucial role in viral entry into host cells—it mediates both attachment and fusion. It's become a key research target precisely because of how the virus interacts with the host receptor, ACE2. Understanding how the Spike protein binds and how mutations like the E484K variant change things is essential for studying viral transmission and immune response. This work contributes significantly to vaccine and therapeutic development efforts, though the landscape continues to evolve.

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.

1. ACE2-Spike Protein Interaction Studies

This recombinant SARS-CoV-2 Spike RBD (E484K) variant—with confirmed binding activity to ACE2 (EC₅₀: 6.597–8.187 ng/ml)—is a validated tool to investigate how the E484K mutation alters binding kinetics/affinity versus wild-type or other variants. The C-terminal mFc tag simplifies immobilization/detection in SPR, BLI, or ELISA. Results can directly contextualize mutation-driven changes in receptor recognition using the established baseline.

2. Neutralizing Antibody Development and Screening

The biologically active E484K RBD—with confirmed binding to anti-Spike antibodies (EC₅₀: 21.54–26.77 ng/ml)—is a robust immunogen for monoclonal antibody generation and a reliable screening antigen for cross-reactive clones. The mFc tag eases purification and immobilization in high-throughput assays. Its activity ensures consistent performance in evaluating antibody efficacy against the E484K variant.

3. Variant-Specific Binding Assay Development

This E484K mutant RBD—with validated functional activity—is ideal for developing diagnostic assays to differentiate immune responses to this variant. Mammalian expression ensures native-like glycosylation, enhancing relevance to viral physiology. Low endotoxin levels and confirmed activity make it suitable for functional ELISA or other immunoassays, supporting reference standard development for variant-specific antibody testing.

4. Structure-Function Relationship Studies

The correctly folded, biologically active E484K RBD—purified to >90% purity—serves as a reliable model to dissect how the E484K mutation impacts folding, stability, and binding. Techniques like DSC, CD spectroscopy, or HDX-MS can compare mutant vs. wild-type RBD, with the mFc tag aiding purification for biophysical analyses. Confirmed activity validates results by ensuring the protein retains native-like structure-function relationships.

5. Competitive Binding and Epitope Mapping Studies

This bioactive E484K RBD—which binds both ACE2 and anti-Spike antibodies—acts as a validated competitor/reference in epitope mapping. It works in competitive ELISA or flow cytometry to identify antibodies retained/lost against the E484K variant. The mFc tag simplifies detection in multi-protein assays, while confirmed activity ensures consistent performance in dissecting mutation-driven epitope changes.

Final Recommendation & Action Plan

This mammalian-expressed, E484K-mutant Spike RBD (319–541 aa) with a C-terminal mFc tag is highly reliable for its intended applications due to its confirmed bioactivity via ELISA—a critical validation milestone. Leverage its consistent performance to study mutation-driven changes in ACE2 binding, screen neutralizing antibodies, or develop variant-specific assays. Always include wild-type RBD as a control to contextualize E484K effects, and use the mFc tag to streamline purification/detection. For structural studies, the tag may require removal (via protease cleavage) for high-resolution data, but its presence does not compromise functional assays. Overall, this protein is a robust tool for variant-focused SARS-CoV-2 research—prioritize comparative studies with wild-type to maximize insight into the E484K mutation’s impact.