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Monoclonal Antibody for SARS-CoV-2 (Covid-19) Spike S1 Protein

$450.00$3,500.00

Item Cat No.: MABCV19

Antibody: Mouse Anti-Covid19 S1 Monoclonal Antibody

Concentration: 0.25 mg/ml purified IgG

Application: Validated by ELISA

Reactivity: Covid-19 virus, S1 protein

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Model of the external structure of the SARS-CoV-2 virion

Blue: envelope
Turquoise: spike glycoprotein (S)
Red: envelope proteins (E)
Green: membrane proteins (M)
Orange: glycan


Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Spike (S) glycoprotein (sometimes also called spike protein) is the largest of the four major structural proteins found on the surface of Covid-19 virion.

The function of the spike glycoprotein is to mediate viral entry into the host cell by first interacting with molecules on the exterior cell surface and then fusing the viral and cellular membranes. Spike glycoprotein is a class I fusion protein that contains two regions, known as S1 and S2, responsible for these two functions. The S1 region contains the receptor-binding domain that binds to receptors on the cell surface. Coronaviruses use a very diverse range of receptors; SARS-CoV (which causes SARS) and SARS-CoV-2 (which causes COVID-19) both interact with angiotensin-converting enzyme 2 (ACE2). The S2 region contains the fusion peptide and other fusion infrastructure necessary for membrane fusion with the host cell, a required step for infection and viral replication. Spike glycoprotein determines the virus’ host range (which organisms it can infect) and cell tropism (which cells or tissues it can infect within an organism).

The S1 region of the spike glycoprotein is responsible for interacting with receptor molecules on the surface of the host cell in the first step of viral entry. S1 contains two domains, called the N-terminal domain (NTD) and C-terminal domain (CTD). Depending on the coronavirus, either or both domains may be used as receptor-binding domains (RBD). The CTD is responsible for the interactions of SARS-CoV-2 with their receptor angiotensin-converting enzyme 2 (ACE2). The CTD of these viruses can be further divided into two subdomains, known as the core and the extended loop or receptor-binding motif (RBM), where most of the residues that directly contact the target receptor are located. Within coronavirus lineages, the S1 region is less well conserved than S2. Within the S1 region, the NTD is more conserved than the CTD.

Molecular structure of a SARS-CoV-2 spike protein trimer in the pre-fusion conformation, with a single monomer highlighted. The S1 NTD is shown in blue and the S1 CTD (which serves as the receptor-binding domain) is shown in pink. Helices show in orange and cyan form parts of S2 that will undergo conformational changes during fusion. The black bar at the bottom indicates the position of the viral membrane. From PDB: 6VSB​.


 

 

Molecular structure of a SARS-CoV-2 spike protein trimer in the pre-fusion conformation, with a single monomer highlighted.

The S1 NTD is shown in blue and the S1 CTD (which serves as the receptor-binding domain) is shown in pink. Helices show in orange and cyan form parts of S2 that will undergo conformational changes during fusion. The black bar at the bottom indicates the position of the viral membrane.

From PDB: 6VSB​.

QHD43416.1 SARS-CoV-2 Spike protein

MFVFLVLLPLVSSQCVNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHV
SGTNGTKRFDNPVLPFNDGVYFASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPF
LGVYYHKNNKSWMESEFRVYSSANNCTFEYVSQPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPI
NLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLTPGDSSSGWTAGAAAYYVGYLQPRTFLLKYN
ENGTITDAVDCALDPLSETKCTLKSFTVEKGIYQTSNFRVQPTESIVRFPNITNLCPFGEVFNATRFASV
YAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIAD
YNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNGVEGFNCYF
PLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNFNFNGLTGTGVLTESNKKFL
PFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPVAIHADQLT
PTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTNSPRRARSVASQSIIAYTMSLG
AENSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGI
AVEQDKNTQEVFAQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDC
LGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIG
VTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDI
LSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLM
SFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHWFVTQRNFYEPQIITTDNT
FVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRLNEVA
KNLNESLIDLQELGKYEQYIKWPWYIWLGFIAGLIAIVMVTIMLCCMTSCCSCLKGCCSCGSCCKFDEDD
SEPVLKGVKLHYT


The entire S1 domain (yellow highlight) was tagged with His and purified from human embryonic kidney HEK293 cells, and used as antigen for monoclonal antibody generation.

Description

Monoclonal antibodies are vital for developing sandwich ELISA detection system for Covid-19 (SARS-CoV-2), including lateral flow cassette. BiCell Scientific has developed mouse monoclonal antibodies against the Spike S1 protein of Covid-19 and validated the antibodies against the purified S1 protein as well as the Covid-19 virus from ATCC. These monoclonal antibodies are also useful for detection of virus in tissue samples or quantitation of virus abundance in detergent dissolved samples that have been infected by virus.

Mouse monoclonal antibody (mAb) production

High affinity hybridoma clones (49 clones) were selected from 400 screened clones and continuously cultured to allow hybridoma maturation in vitro.


 

 

Hybridoma Maturation
The majority of the 49 shortlisted high affinity binders matured over continuous in vitro culture. 10 clones lost the antibody expression due to chromosomal re-arrangement.

Antibody clone name (below).

Procedure: plate was coated with antigen – S1 protein at 10 ug/ml in PBS, followed by incubation with hybridoma supernatant for 1 hr and anti-mouse-HRP for 1 hr. HRP substrate (blue color) develops within 5 min. No acid was added. Image was taken with iPhone.

Sandwich ELISA development

Four high affinity clones were selected for sandwich ELISA development and manufactured to milligram level.

S1P2B5, S1D1D7, S1D2C8: capture antibody;
S1D1E5: detection antibody, conjugated to HRP.

Sandwich ELISA
Procedure: plate was coated with detection antibody at 50 ug/ml in PBS, followed by incubation with antigen or virus for 1hr and S1D1E5-HRP antibody (50 ug/ml) for 1hr. HRP substrate (blue color) develops within 5 min. No acid was added. Image was taken with iPhone.

Milestone: Sandwich ELISA is able to detect S1 protein as low as 1 ng/ml (0.001 ug/ml). Covid-19 virus, when treated with detergent, can be detected as low as 0.1 ug/ml (estimated by comparing to S1 protein).

An ELISA kit based upon S1D1E5 and S1D2C8 is available at Cat No: ELICV19.

The highly mutated Omicron variant (B.1.1.529) may cause loss of binding of mAbs to S1 protein. BiCell Scientific has tested the binding of mAbs to Omicron variant S1 protein and compared it to wild type (WT) S1 protein.

The following mutations are present in Omicron variant S1 protein: A67V, del69-70, T95I, G142D, del143-145, del211, L212I, ins214EPE, G339D, S371L, S373P, S375F, K417N, N440K, G446S, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y, Y505H, T547K, D614G, H655Y, N679K, P681H.

Four mAb clones were tested for binding difference between wild type (WT) S1 protein and Omicron variant S1 protein. One clone: S1P2B5 was affected by Omicron mutations.

Procedure: plate was coated with antigen – S1 protein (WT or Omicron variant) at 10 ug/ml in PBS, followed by incubation with antibody for 1 hr and anti-mouse-HRP for 1 hr. HRP substrate (blue color) develops within 5 min. No acid was added. Image was taken with iPhone.

Host/Isotype: Mouse/IgG

Class: Monoclonal

Immunogen: Recombinant Covid-19 S1 protein

Conjugation: Unconjugated

Purification: Affinity chromatography

Storage buffer: PBS, pH 7.2, 0.1% sodium azide

Storage condition: –20°C


For Research Use Only. Not for use in clinical diagnostics.

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Be the first to review “Monoclonal Antibody for SARS-CoV-2 (Covid-19) Spike S1 Protein”

"I am really impressed with your approach. We tried multiple times previously to create monoclonal and polyclonal antibodies to claudin-2 and MLCK1. We have had limited success generating polyclonals and no success generating monoclonals. You have generated outstanding monoclonals to both. I look forward to continuing to work with you."

Jerrold R. Turner, M.D., Ph.D.

Brigham and Women’s Hospital | Harvard Medical School

"The polyclonal antibody you generated for KIAA0408 is stunning! KIAA0408 is a novel cilium molecule that has never been studied. So, clearly there will be a lot of demand for it as we have discovered a very interesting finding and the story will be published in a high impact journal. I am strongly inclined to generate monoclonal antibody for this protein too and we should think about patenting it."

Univ.-Prof. Jay Gopalakrishnan PhD

Heinrich-Heine-Universität | Universitätsklinikum Düsseldorf

"Your ARL13B antibody works beautifully!!! We’re so happy to have a cilia-specific antibody made in rat! I can send you high resolution images to be posted on your website."

Julie Craft Van De Weghe, PhD

School of Medicine | University of Washington

"The assay is a homophilic interaction mediated cell adhesion on purified protein (in this case, immobilized purified Pcdhga9 to Pcdhga9 expressed on cell surface). Compared to control, cell adhesion is reduced in the presence of Pcdhga9 monoclonal antibody supernatants!"

Divyesh Joshi, PhD

School of Medicine | Yale University

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