Human embryonic kidney cell, HEK293-derived sars-cov Spike RBD protein Arg306-Phe527, with a C-terminal 6-His tag
>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.10 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
32-38 kDa, under reducing conditions
Measured by its binding ability in a functional ELISA with Recombinant Human ACE-2 His-tag (Catalog # 933-ZN).
Recombinant SARS-CoV Spike RBD His-tag Protein, CF Scientific Data Examples
Recombinant SARS-CoV Spike RBD His-tag Protein Bioactivity
Recombinant SARS-CoV Spike RBD His-tag (Catalog # 10583-CV) binds Recombinant Human ACE-2 His-tag (933-ZN) in a functional ELISA.
Recombinant SARS-CoV Spike RBD His-tag Protein SDS-PAGE
2 μg/lane of Recombinant SARS-CoV Spike RBD His-tag Protein (Catalog # 10583-CV) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 32-38 kDa.
Detection of SARS-CoV Spike RBD Protein bound to ACE-2 expressing cells by flow cytometry.
In a functional flow cytometry test, (A) Recombinant SARS-CoV Spike RBD His-tag Protein (Catalog # 10583-CV) binds to HEK293 human embryonic kidney cell line transfected with recombinant human ACE-2 and EGFP. Ligand binding was detected by staining cells with APC-conjugated anti-His Monoclonal Antibody (IC050A), which does not stain the cells in the absence of recombinant protein (B).
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitute at 500 μg/mL in PBS.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70 °C as supplied.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
3 months, -20 to -70 °C under sterile conditions after reconstitution.
Background: Spike RBD
SARS-CoV was discovered in association with cases of severe acute respiratory syndrome (SARS) that infected more than 8,000 persons with over 900 fatalities worldwide in 2002-2003 (1). It belongs to a family of viruses known as coronaviruses that also include MERS and SARS-CoV2 that causes the global pandemic coronavirus disease 2019 (Covid-19). Coronavirus is commonly comprised of four structural proteins: Spike protein(S), Envelope protein (E), Membrane protein (M) and Nucleocapsid protein (N) (1). SARS-CoV S Protein is a trimeric type-I membrane glycoprotein that mediates membrane fusion and viral entry. As with most coronaviruses, proteolytic cleavage of the S protein into two distinct peptides, S1 and S2 subunits, is required for activation. The S1 subunit is focused on attachment of the protein to the host receptor while the S2 subunit is involved with cell fusion (2-4). A metallopeptidase, angiotensin-converting enzyme 2 (ACE-2), has been identified as a functional receptor for SARS-CoV through interaction with a receptor binding domain (RBD) located at the C-terminus of S1 subunit (5, 6). Based on amino acid (aa) sequence homology, the S protein of SARS-CoV shares 75% and 31% homology with S protein of SARS-CoV2 and MERS, respectively. Before binding to the ACE-2 receptor, structural analysis of the S1 trimer shows that only one of the three RBD domains in the trimeric structure is in the "up" conformation. This is an unstable and transient state that passes between trimeric subunits but is nevertheless an exposed state to be targeted for neutralizing antibody therapy (7). Antibodies to S protein especially the S1 subunit of SARS-CoV have been shown to inhibit interaction with the ACE-2 receptor, confirming S1 subunit as an attractive target for vaccinations or antiviral therapy (8).
Rota, P.A. et al. (2003) Science 300:1394.
Bosch, B.J. et al. (2003). J. Virol. 77:8801.
Belouzard, S. et al. (2009) Proc. Natl. Acad. Sci. USA 106:5871.
Millet, J.K. and G. R. Whittaker (2015) Virus Res. 202:120.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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