Biolegend, 560306, Biotinylated Recombinant SARS-CoV-2 B.1.1.7 Spike Protein S1 (carrier-free), 100μg

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) is a respiratory virus which causes coronavirus disease 2019 (COVID-19). The coronavirus spike (S) glycoprotein is a class I viral fusion protein on the outer envelope of the virion that plays a critical role in viral infection by recognizing host cell receptors and mediating fusion of the viral and cellular membranes. The S glycoprotein is synthesized as a precursor protein consisting of ~1,300 amino acids that is then cleaved into an amino (N)-terminal S1 subunit (~700 amino acids) and a carboxyl (C)-terminal S2 subunit (~600 amino acids). Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Triggered by receptor binding, proteolytic processing and/or acidic pH in the cellular compartments, the class I viral fusion protein undergoes a transition from a metastable pre-fusion state to a stable post-fusion state during infection, in which the receptor-binding subunit is cleaved, and the fusion subunit undergoes large-scale conformational rearrangements to expose the hydrophobic fusion peptide, induce the formation of a six-helix bundle, and bring the viral and cellular membranes close for fusion. The trimeric SARS coronavirus (SARS-CoV-2) S glycoprotein consisting of three S1-S2 heterodimers binds the cellular receptor angiotensin-converting enzyme 2 (ACE2) and mediates fusion of the viral and cellular membranes through a pre- to post-fusion conformation transition. The emergence of the B.1.1.7 variant of SARS-CoV-2, also known as the variant of concern (VOC) 202012/01 strain, was first identified in the United Kingdom (UK) in 2020. Additionally, the B.1.1.7 was significantly more transmissible than other preexisting variants. The B.1.1.7 variant contains a significant mutation of interest in the RBD, the asparagine (N) to tyrosine (Y) mutation at position 501 (N501Y), which has been shown to result in enhanced binding affinity for hACE-2.
100μg
Source: Biotinylated recombinant SARS-CoV-2 B.1.1.7 Spike protein S1, amino acid Val16-Arg685 (Accession No. QHD43416.1), with (HV69-70del, Y144del, N501Y, A570D, P681H) and a C-terminal 8His-Avi tag was expressed in CHO cells. SARS-CoV-2 B.1.1.7 Spike Protein S1 Avi-tag was site-specifically biotinylated by enzyme BirA.
Molecular Mass: The 703 amino acid recombinant protein has a predicted molecular mass of approximately 78 kD. The DTT-reduced and non-reduced protein migrates at approximately 80 - 115 kD by SDS-PAGE. The predicted N-terminal amino acid is Val.
Purity: > 95%, as determined by Coomassie stained SDS-PAGE.
Formulation: 0.22 µm filtered protein solution is in 10 mM Sodium Phosphate buffer, pH 7.5
Endotoxin Level: Less than 0.1 EU per µg cytokine as determined by the LAL method.
Concentration: 25 µg size is bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & Handling: Unopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
Activity: When recombinant human ACE2- Fc (Cat. No. 793202) is immobilized at 1 µg/mL, biotinylated recombinant SARS-CoV-2 B.1.1.7 Spike protein S1 binds in a dose-dependent manner. The ED50 range for this effect is 3 - 18 ng/mL. HRP Avidin (Cat. No. 405103) was used to detect the binding.
Application: Bioassay
Application Notes: BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are validated in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at [email protected].
Structure: Monomer
Distribution: SARS-CoV-2
Function: Attaches the virion to the cell membrane by interacting with host receptor (ACE2) initiating the infection
Interaction: Ciliated cells in nasal mucosa and bronchus
Ligand/Receptor: ACE2
Bioactivity: Measured by its ability to bind recombinant human ACE2
Cell Type: B cells, Endothelial cells, Macrophages, Monocytes, NK cells, T cells, Th1
Biology Area: Adaptive Immunity, Immunology, Innate Immunity
Antigen References: Lu R, et al. 2020. Lancet. 395:565-574. Li F. 2016. Annu Rev Virol. 29;3(1):237-261. Belouzard S, et al. 2012. Viruses. 4:1011-33. Song W, et al. 2018. PLoS Pathog. 14:e1007236 Li F, et al. 2020. Nature. 581:221. TJ Yang, et al. 2021. Nature structural & Molecular Biology. 28:731-739. Kidd M, et al. 2021. The Journal of Infectious Diseases. 224:928-929. Davis NG, et al. 2021. Science. 372 (6538): eabg305.
Gene ID: 43740568
UniProt: View information about S1 on UniProt.org
Regulatory Status: RUO
Other Names: S glycoprotein, S Protein, SARS-COV-2 S protein, SARS-COV-2 Spike glycoprotein, SARSCOV2 Spike protein, SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein, Spike protein, UK variant, S1, Coronavirus spike protein