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Variants package of SARS CoV-2 Spike (S) protein mutation – Peptide library

SARS-CoV-2 Spike (S) glycoprotein

Spike (S) glycoprotein corresponds to one of the leading targets for COVID-19 disease. Present on the surface of Sars-CoV-2 virus, Spike S protein in a class I fusion protein that allows the virus to enter host cells.

Variants package available – Reference #SB072

Some proteins of Sars-CoV-2 are identified as leading targets for COVID-19 therapies. SB-PEPTIDE offers a special pack pre-made peptide libraries of Spike protein including peptides from COVID-19 variants: UK COVID-19 variant B.1.1.7, South Africa COVID-19 variant B.1.351, Brazil COVID-19 variant B.1.1.248, Indian COVID-19 variant B.1.617 and California COVID-19 variant B.1.429 CAL.20C. SB-PEPTIDE offers additional plates containing only peptides with Spike S protein mutation of COVID-19 B.1.1.7, B.1.3.5.1, B.1.1.248, B.1.617 and B.1.429 CAL.20C (cited below).

Variants package and Spike (S) glycoprotein peptide library can be used for T-cell assays, immune monitoring, antigen specific T-cell stimulation, T-cell expansion and cellular immune response.

Spike (S) protein – peptide library reference #SB043

Technical specification – Ref: #SB072

heavy SIL adalimumab buy Peptides length : 15 aa
spike s mutation protein buy peptide library Offset number : 11 aa
variants package of covid-19 sars cov 2 peptide library Amount : 0,5mg or 5*0,5mg (for each peptide)
adalimumab peptide standard price Quality : Crude, 100% LC-MS
adalimumab peptide standard synthesis Counter-Ion : TFA Salts (see option TFA removal)
Peptide library synthesis abeta peptide Delivery format : Lyophilized or in solution, in 96-well plate or microtubes
COVID-19 variants peptide library buy Price : Ask for your quote
adalimumab internal standard solubility guidelines Peptide Solubility Guideline

References

1- Ou, X., Liu, Y., Lei, X. et al. Nat Commun 11, 1620 (2020)
Characterization of spike glycoprotein of SARS-CoV-2 on virus entry and its immune cross-reactivity with SARS-CoV

 

Since 2002, beta coronaviruses (CoV) have caused three zoonotic outbreaks, SARS-CoV in 2002–2003, MERS-CoV in 2012, and the newly emerged SARS-CoV-2 in late 2019. However, little is currently known about the biology of SARS-CoV-2. Here, using SARS-CoV-2 S protein pseudovirus system, we confirm that human angiotensin converting enzyme 2 (hACE2) is the receptor for SARS-CoV-2, find that SARS-CoV-2 enters 293/hACE2 cells mainly through endocytosis, that PIKfyve, TPC2, and cathepsin L are critical for entry, and that SARS-CoV-2 S protein is less stable than SARS-CoV S. Polyclonal anti-SARS S1 antibodies T62 inhibit entry of SARS-CoV S but not SARS-CoV-2 S pseudovirions. Further studies using recovered SARS and COVID-19 patients’ sera show limited cross-neutralization, suggesting that recovery from one infection might not protect against the other. Our results present potential targets for development of drugs and vaccines for SARS-CoV-2.

2- Yasunori W et al. Science (2020)
Site-specific glycan analysis of the SARS-CoV-2 spike

 

SARS-CoV-2 spike protein, elaborated

Vaccine development for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is focused on the trimeric spike protein that initiates infection. Each protomer in the trimeric spike has 22 glycosylation sites. How these sites are glycosylated may affect which cells the virus can infect and could shield some epitopes from antibody neutralization. Watanabe et al. expressed and purified recombinant glycosylated spike trimers, proteolysed them to yield glycopeptides containing a single glycan, and determined the composition of the glycan sites by mass spectrometry. The analysis provides a benchmark that can be used to measure antigen quality as vaccines and antibody tests are developed.

Science this issue p. 330

Abstract

The emergence of the betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), represents a considerable threat to global human health. Vaccine development is focused on the principal target of the humoral immune response, the spike (S) glycoprotein, which mediates cell entry and membrane fusion. The SARS-CoV-2 S gene encodes 22 N-linked glycan sequons per protomer, which likely play a role in protein folding and immune evasion. Here, using a site-specific mass spectrometric approach, we reveal the glycan structures on a recombinant SARS-CoV-2 S immunogen. This analysis enables mapping of the glycan-processing states across the trimeric viral spike. We show how SARS-CoV-2 S glycans differ from typical host glycan processing, which may have implications in viral pathobiology and vaccine design.

3- Alexandra C. Walls et al. Cell (2020)
Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein

 

The emergence of SARS-CoV-2 has resulted in >90,000 infections and >3,000 deaths. Coronavirus spike (S) glycoproteins promote entry into cells and are the main target of antibodies. We show that SARS-CoV-2 S uses ACE2 to enter cells and that the receptor-binding domains of SARS-CoV-2 S and SARS-CoV S bind with similar affinities to human ACE2, correlating with the efficient spread of SARS-CoV-2 among humans. We found that the SARS-CoV-2 S glycoprotein harbors a furin cleavage site at the boundary between the S1/S2 subunits, which is processed during biogenesis and sets this virus apart from SARS-CoV and SARS-related CoVs. We determined cryo-EM structures of the SARS-CoV-2 S ectodomain trimer, providing a blueprint for the design of vaccines and inhibitors of viral entry. Finally, we demonstrate that SARS-CoV S murine polyclonal antibodies potently inhibited SARS-CoV-2 S mediated entry into cells, indicating that cross-neutralizing antibodies targeting conserved S epitopes can be elicited upon vaccination.

4-Wang P. et al. BioRxiv. (2021)
Increased Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7 to Antibody Neutralization

 

The Covid-19 pandemic has ravaged the globe, and its causative agent, SARS-CoV-2, continues to rage. Prospects of ending this pandemic rest on the development of effective interventions. Single and combination monoclonal antibody (mAb) therapeutics have received emergency use authorization 1,2 , with more in the pipeline 3-6 . Furthermore, multiple vaccine constructs have shown promise 7 , including two with ~95% protective efficacy against Covid-19 8,9 . However, these interventions were directed toward the initial SARS-CoV-2 that emerged in 2019. Considerable viral evolution has occurred since, including variants with a D614G mutation 10 that have become dominant. Viruses with this mutation alone do not appear to be antigenically distinct, however 11 . Recent emergence of new SARS-CoV-2 variants B.1.1.7 in the UK 12 and B.1.351 in South Africa 13 is of concern because of their purported ease of transmission and extensive mutations in the spike protein. We now report that B.1.1.7 is refractory to neutralization by most mAbs to the N-terminal domain (NTD) of spike and relatively resistant to a number of mAbs to the receptor-binding domain (RBD). It is modestly more resistant to convalescent plasma (~3 fold) and vaccinee sera (~2 fold). Findings on B.1.351 are more worrisome in that this variant is not only refractory to neutralization by most NTD mAbs but also by multiple individual mAbs to the receptor-binding motif on RBD, largely due to an E484K mutation, although some mAb combinations retain activity. Moreover, B.1.351 is markedly more resistant to neutralization by convalescent plasma (~11-33 fold) and vaccinee sera (~6.5-8.6 fold). B.1.351 and emergent variants 14,15 with similar spike mutations present new challenges for mAb therapy and threaten the protective efficacy of current vaccines.