Recombinant SARS-CoV-2 BA.2 Spike S1 NTD His-tag Protein, CF

2 μg/lane of Recombinant SARS-CoV-2 BA.2 Spike S1 Subunit NTD His-tag Protein (Catalog # 11147-CV) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 53-59 kDa.

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

Recombinant SARS-CoV-2 BA.2 Spike S1 NTD His-tag Protein, CF Summary

• Additional Information: Omicron Variant
• Details of Functionality: Bioassay data are not available.
• Source: Human embryonic kidney cell, HEK293-derived sars-cov-2 Spike S1 Subunit protein
  Val16-Leu303 (Thr19Ile, Leu24del, Pro25del, Pro26del, Ala27Ser, Gly142Asp, Val213Gly) 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: 33 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: 53-59 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 BA.2 Spike S1 NTD 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 can be further divided into an N-terminal domain (NTD) and a receptor binding domain (RBD). The SARS-CoV-2 NTD shares 50% and 20% amino acid (aa) sequence identity with the NTD of SARS-CoV-1 and MERS-CoV, respectively. The NTD is reported to bind L-SIGN and DC-SIGN in cells that don't express the ACE2 receptor (6). Despite being heavily glycosylated, the NTD is capable of eliciting an immune response to produce potent neutralization antibodies, although at a reduced level than the ones targeting the RBD. Three immunogenic regions have been identified in the NTD: aa 14-20, aa 140-158, and aa 245-264 (7). Antibody cocktails targeting both NTD and RBD could provide better protection against SARS-CoV-2 infection. Seven mutation are found in the NTD of Omicron BA.2 variant.

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. Soh, W.T. et al. (2020) bioRxiv doi: https://doi.org/10.1101/2020.11.05.369264.
7. McCallum, M. et al. (2021) Cell 184:2332.

Bioinformatics

• Uniprot:
  • YP_009724390.1(Llama)