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SARS-CoV-2 Spike RBD LlaMABodyTM Bivalent VHH HuIgG2 Fusion Antibody

R&D Systems, part of Bio-Techne | Catalog # LMAB10731

Recombinant Monoclonal Antibody. Bivalent Llama VHH domain, Human IgG2 Fusion Antibody.
R&D Systems, part of Bio-Techne
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LMAB10731-100
LMAB10731-SP

Key Product Details

Species Reactivity

SARS-CoV-2

Applications

Blockade of Receptor-ligand Interaction

Label

Unconjugated

Antibody Source

Recombinant Monoclonal Llama VHH domain Clone # L009.1.32H

Product Specifications

Immunogen

Human embryonic kidney cell HEK293-derived SARS-CoV-2 Spike RBD as immunogen for bivalent Llama VHH-Human IgG2 Fusion Antibody.
Arg319-Phe541
Accession # YP_009724390.1

Specificity

Clone L009.1.32H is a bivalent Llama VHH-Human IgG2 Fusion Antibody that detects SARS-CoV-2 Spike RBD in direct ELISAs. Antibody construct is depicted below.SARS-CoV-2 Spike RBD SpecificLlama VHH domainLlama Hinge Human IgG2N-terminusC-terminus

Clonality

Monoclonal

Host

Llama

Isotype

VHH domain

Endotoxin Level

<0.10 EU per 1 μg of the antibody by the LAL method.

Scientific Data Images

SARS-Cov-2 Spike 1 protein binding to ACE-2-transfected Human Cell Line is Blocked by SARS-Cov-2 Spike RBD Antibody.

In a functional flow cytometry test, Recombinant SARS-Cov-2 Spike 1 His-tagged protein (10522-CV) binds to HEK293 human embryonic kidney cell line transfected with recombinant human ACE-2 and eGFP. (A) Binding is completely blocked by 50 µg/mL of Llama Anti-SARS-Cov-2 Spike RBD Monoclonal Antibody (Catalog # LMAB10731) but not by (B) Llama IgG1 Control. Protein binding was detected with Mouse Anti-His APC-conjugated Monoclonal Antibody (IC050A). Staining was performed using our Staining Membrane-Associated Proteins protocol.

Applications

Application
Recommended Usage

Blockade of Receptor-ligand Interaction

50 µg/mL
Sample: In a functional flow cytometry test, 50 μg/mL of Llama Anti-SARS-Cov-2 Spike RBD Antibody(Catalog # LMAB10731) will block the binding of Recombinant SARS-Cov-2 Spike 1 His-tagged protein (Catalog # 10522-CV) to HEK293 human embryonic kidney cell line transfected with recombinant human ACE-2.

Formulation, Preparation, and Storage

Purification

Protein A or G purified from cell culture supernatant

Reconstitution

Reconstitute at 0.5 mg/mL in sterile PBS. For liquid material, refer to CoA for concentration.

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Formulation

Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied either lyophilized or as a 0.2 µm filtered solution in PBS.

Shipping

Lyophilized product is shipped at ambient temperature. Liquid small pack size (-SP) is shipped with polar packs. Upon receipt, store 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.
  • 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: Spike RBD

SARS-CoV-2, which causes the global pandemic coronavirus disease 2019 (Covid-19), belongs to a family of viruses known as coronaviruses that are commonly comprised of four structural proteins: Spike protein(S), Envelope protein (E), Membrane protein (M), and Nucleocapsid protein (N) (1). SARS-CoV-2 Spike Protein (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 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 (3-5). Based on structural biology studies, the receptor binding domain (RBD), located in the C-terminal region of S1, can be oriented either in the up/standing or down/lying state (6). The standing state is associated with higher pathogenicity and both SARS-CoV-1 and MERS can access this state due to the flexibility in their respective RBDs. A similar two-state structure and flexibility is found in the SARS-CoV-2 RBD (7). Based on amino acid (aa) sequence homology, the SARS-CoV-2 S1 subunit RBD has 73% identity with the RBD of the SARS-CoV-1 S1 RBD, but only 22% homology with the MERS S1 RBD. The low aa sequence homology is consistent with the finding that SARS and MERS bind different cellular receptors (8). The S Protein of the SARS-CoV-2 virus, like the SARS-CoV-1 counterpart, binds Angiotensin-Converting Enzyme 2 (ACE2), but with much higher affinity and faster binding kinetics (9). Before binding to the ACE2 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 (10). Polyclonal antibodies to the RBD of the SARS-CoV-2 protein have been shown to inhibit interaction with the ACE2 receptor, confirming RBD as an attractive target for vaccinations or antiviral therapy (11). 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 virus (12). Lastly, it has been demonstrated the S Protein can invade host cells through the CD147/EMMPRIN receptor and mediate membrane fusion (13, 14).

References

  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. Yuan, Y. et al. (2017) Nat. Commun. 8:15092.
  7. Walls, A.C. et al. (2010) Cell 180:281.
  8. Jiang, S. et al. (2020) Trends. Immunol. https://doi.org/10.1016/j.it.2020.03.007.
  9. Ortega, J.T. et al. (2020) EXCLI J. 19:410.
  10. Wrapp, D. et al. (2020) Science 367:1260.
  11. Tai, W. et al. (2020) Cell. Mol. Immunol. https://doi.org/10.1016/j.it.2020.03.007.
  12. Okba, N. M. A. et al. (2020). Emerg. Infect. Dis. https://doi.org/10.3201/eid2607.200841.
  13. Wang, X. et al. (2020) https://doi.org/10.1038/s41423-020-0424-9.
  14. Wang, K. et al. (2020) bioRxiv https://www.biorxiv.org/content/10.1101/2020.03.14.988345v1.

Long Name

Spike Receptor Binding Domain

Entrez Gene IDs

3200426 (HCoV-HKU1); 14254594 (MERS-CoV); 1489668 (SARS-CoV); 43740568 (SARS-CoV-2)

Gene Symbol

S

UniProt

Additional Spike RBD Products

Product Documents

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Note: Certificate of Analysis not available for kit components.

Product Specific Notices

For research use only

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