Recombinant SARS-CoV-2 B.1.1.7 Spike S1 His-tag Protein, CF

Recombinant SARS-CoV-2 B.1.1.7 Spike S1 Subunit His-tag Protein (Catalog # 11137-CV) binds Recombinant Human ACE-2 His-tag (933-ZN) in a functional ELISA.

2 μg/lane of Recombinant SARS-CoV-2 B.1.1.7 Spike S1 Subunit His-tag Protein (Catalog # 11137-CV) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 106 - 123 kDa.

• Reactivity: V
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant SARS-CoV-2 B.1.1.7 Spike S1 His-tag Protein, CF Summary

• Additional Information: Alpha Variant (UK)
• Details of Functionality: Measured by its binding ability in a functional ELISA with Recombinant Human ACE-2 His-tag (Catalog # 933-ZN).
• Source: Human embryonic kidney cell, HEK293-derived sars-cov-2 Spike S1 Subunit protein
  Val16-Pro681 (His69del, Val70del, Tyr145del, Asn501Tyr, Ala570Asp, Asp614Gly, Pro681His), with a C-terminal 6-His tag
• Accession #: YP_009724390.1
• N-terminal Sequence: Val16
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 75 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 106-123 kDa, under reducing conditions.

Packaging, Storage & Formulations

• 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.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant SARS-CoV-2 B.1.1.7 Spike S1 His-tag Protein, CF

• SARS-CoV-2
• Spike S1 Subunit

Background

SARS-CoV-2, which causes the global pandemic coronavirus disease 2019 (Covid-19), belongs to a family of viruses known as coronaviruses that also include MERS-CoV and SARS-CoV-1. Coronaviruses are commonly comprised of four structural proteins: Spike protein (S), Envelope protein (E), Membrane protein (M) and Nucleocapsid protein (N) (1). The SARS-CoV-2 S protein is a glycoprotein that mediates membrane fusion and viral entry. The S protein is homotrimeric, with each ~180-kDa monomer consisting of two subunits, S1 and S2 (2). In SARS-CoV-2, as with most coronaviruses, proteolytic cleavage of the S protein into 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 (3-5). The S1 subunit of SARS-CoV-2 shares 65% and 22% amino acid sequence identity with that of SARS-CoV-1 and MERS, respectively. The S Protein of the SARS‑CoV‑2 virus, like the SARS-CoV-1 counterpart, binds a metallopeptidase, Angiotensin-Converting Enzyme 2 (ACE-2), but with much higher affinity and faster binding kinetics through the receptor binding domain (RBD) located in the C-terminal region of S1 subunit (6). It has been demonstrated that the S Protein can invade host cells through the CD147/EMMPRIN receptor and mediate membrane fusion (7,  8). Polyclonal antibodies to the RBD of the SARS-CoV-2 protein have been shown to inhibit interaction with the ACE-2 receptor, confirming RBD as an attractive target for vaccinations or antiviral therapy (9). There is also promising work showing that the RBD may be used to detect presence of neutralizing antibodies present in a patient's bloodstream, consistent with developed immunity after exposure to the SARS-CoV-2 (10). Several emerging SARS-CoV-2 genomes have been identified including the B 1.1.7 (United Kingdom) variant (11). The B 1.1.7 variant contains 1 significant mutation of interest in the RBD domain, N501Y, which has been shown to result in enhanced binding affinity for hACE-2 (12). Further, the B 1.1.7 variant appears to more easily transmissible, exhibit increased viral loads and, potentially, be associated with higher mortality rates compared to preexisting variants (11, 13).

1. Wu, F. et al. (2020) Nature 579:265.
2. Tortorici, M.A. and D. Veesler (2019) Adv. Virus Res. 105:93.
3. Bosch, B.J. et al. (2003). J. Virol. 77:8801.
4. Belouzard, S. et al. (2009) Proc. Natl. Acad. Sci. 106:5871.
5. Millet, J.K. and G.R. Whittaker (2015) Virus Res. 202:120.
6. Ortega, J.T. et al. (2020) EXCLI J. 19:410.
7. Wang, K. et al. (2020) Sig. Transduct. Target Ther. 5:283.
8. Isabel, et al. (2020) Sci. Rep. 10:14031.
9. Tai, W. et al. (2020) Cell. Mol. Immunol. 17:613.
10. Okba, N.M.A. et al. (2020) Emerg. Infect. Dis. https://doi.org/10.3201/eid2607.200841.
11. Kidd, M. et al. (2021) The Journal of Infectious Diseases 223:1666.
12. Zahradník, J. et al. (2021) Nat. Microbiol. 6:1188.
13. Davies, N.G. (2020) Science 372:eabg3055.

Bioinformatics

• Uniprot:
  • YP_009724390.1(Rabbit)