Recombinant SARS-CoV-2 20C-US S1 Subunit His-tag Protein, CF

Catalog #: 10778-CV Datasheet / COA / SDS

D614G, Q677H

Catalog #	Availability	Size / Price	Qty
10778-CV-100

Recombinant SARS-CoV-2 20C-US S1 Subunit His-tag Protein Binding Activity.

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All Spike S1 Subunit Proteins and Enzymes

Product Details

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Summary Product Datasheets Carrier Free Data Images Reconstitution Calculator Background Related Research Areas

Recombinant SARS-CoV-2 20C-US S1 Subunit His-tag Protein, CF Summary

Product Specifications

Purity

>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

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

Activity

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 (Asp614Gly, Gln677His), with a C-terminal 6-His tag

Accession #

YP_009724390.1

N-terminal Sequence
Analysis

Protein identity confirmed by mass spectrometry

Predicted Molecular Mass

75 kDa

SDS-PAGE

105-117 kDa, under reducing conditions

Product Datasheets

10778-CV

Product Datasheet

COA

SDS

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. 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 could interfere.

10778-CV

Formulation	Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitution	Reconstitute at 500 μg/mL in PBS.
Shipping	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.

Scientific Data

Binding Activity

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Recombinant SARS-CoV-2 20C-US Spike S1 Subunit His-tag (Catalog # 10778-CV) binds Recombinant Human ACE-2 His-tag (933-ZN) in a functional ELISA.

SDS-PAGE

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2 μg/lane of Recombinant SARS-CoV-2 20C-US S1 Subunit His-tag (Catalog # 10778-CV) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 105-117 kDa.

Surface Plasmon Resonance (SPR)

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Recombinant SARS-CoV-2 Spike protein mutant S1subunit D614G Q677H His-tag was immobilized on a Biacore Sensor Chip CM5, and binding to recombinant human ACE-2 (933-ZN) was measured at a concentration range between 0.092 nM and 47.2 nM. The double-referenced sensorgram was fit to a 1:1 binding model to determine the binding kinetics and affinity, with an affinity constant of KD=2.129 nM.

Reconstitution Calculator

Background: Spike S1 Subunit

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 the 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 protein of SARS-CoV-2 shares 65% and 22% amino acid (aa) sequence identity with the S1 protein of SARS-CoV-1 and MERS, respectively. 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 through the receptor binding domain (RBD) located in the C-terminal region of S1 (6). Based on structural biology studies, the RBD can be oriented either in the up/standing or down/lying state with the up/standing state associated with higher pathogenicity (7). Polyclonal antibodies to the RBD of the SARS-CoV-2 S1 protein have been shown to inhibit interaction with the ACE2 receptor, confirming RBD as an attractive target for vaccinations or antiviral therapy (8). It has been demonstrated that the S Protein can invade host cells through the CD147/EMMPRIN receptor and mediate membrane fusion (9, 10). 20C.US is a SARS-CoV-2 variant that was first identified late May 2020 and become the most dominant strain in the US. It has not spread to regions outside the US yet. Among other signature point mutations, two of them are found in the S protein (D614G and Q677H) (11).

References

Wu, F. et al. (2020) Nature 579:265.
Tortorici, M.A. and D. Veesler (2019) Adv. Virus Res. 105:93.
Bosch, B.J. et al. (2003). J. Virol. 77:8801.
Belouzard, S. et al. (2009) Proc. Natl. Acad. Sci. 106:5871.
Millet, J.K. and G.R. Whittaker (2015) Virus Res. 202:120.
Ortega, J.T. et al. (2020) EXCLI J. 19:410.
Yuan, Y. et al. (2017) Nat. Commun. 8:15092.
Tai, W. et al. (2020) Cell. Mol. Immunol. https://doi.org/10.1016/j.it.2020.03.007.
Wang, X. et al. (2020) https://doi.org/10.1038/s41423-020-0424-9.
Wang, K. et al. (2020) bioRxiv https://www.biorxiv.org/content/10.1101/2020.03.14.988345v1.
Pater, A. et al. (2021) bioRxiv https://doi.org/10.1101/2021.01.11.426287.