Anti-SARS-CoV-2 Delta Spike Antibody, P681R Antibody, clone 4C5-B2

Spike glycoprotein (UniProt: P0DTC2; also known as S glycoprotein, E2, Peplomer protein) is encoded by the S (also known as 2) gene (Gene ID: 43740568) in Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 is a positive-strand RNA virus that causes severe respiratory syndrome in human. The mature SARS-CoV-2 contains 4 structural proteins: Envelope (E), Membrane (M), Nucleocapsid (N), and the Spike protein (S). E and M proteins help in viral assembly and N protein is needed for RNA synthesis. The S protein is a single-pass type I, homotrimeric, membrane glycoprotein that is responsible for virus binding and entry into host cell. It is synthesized with a signal peptide (aa 1-12), which is subsequently cleaved off to generate the mature protein that contains an extracellular domain (aa 13-1213), a transmembrane domain (aa 1214-1234), and a cytoplasmic domain 1235-1273). The S protein is further processed into S1 (aa 13-685) and S2 (aa 686-1273) subunits by host cell furin. The presence of a furin polybasic cleavage site in S protein from SARS-CoV-2 sets it apart from S protein in SARS-CoV that possesses a monobasic S1/S2 cleavage site. The S1 subunit has the receptor binding domain (RBD; aa 319-541) that mediates entry of SARS-CoV-2 into sensitive cells through the peptidase domain of host Angiotensin-converting enzyme 2 (ACE2) with high affinity (KD = 15 nM). The S2 domain (aa 686-1213), which is reported to be well conserved, is responsible for membrane fusion. Over the course of the pandemic, SARS-CoV2 has consistently mutated giving rise to various mutants. The Delta SARS-CoV-2-with P681R mutation is shown to efficiently outcompete the Alpha variant in human lung epithelial cells and primary human airway tissues. This mutation is located at the furin cleavage site that separates the spike 1 (S1) and S2 subunits and enhances the replication of the Delta variant on primary human airway cultures. P681R mutation enhances the fusogenicity and pathogenicity of SARS-CoV-2. Clone 4C5-B2 specifically detects the SARS-CoV-2 Spike mutation P681R. (Ref.: Liu, Y., et al. (2022). Cell Rep. 3997); 110829; Shirakawa, K., et al. (2022). Nature. 602(7896); 300-306).

A recombinant fusion protein with a scaffold containing a short Spike peptide QTNSRRRAR.

Quality Control Testing

Evaluated by Western Blotting in lysate from HEK293T cells transiently transfected with SARS-CoV-2 Delta spike B.1.617.2.

Western Blotting Analysis: A 1:500 dilution of this antibody detected SARS-CoV-2 Delta spike protein (P681R) in lysate from HEK293T cells transiently transfected with SARS-CoV-2 Delta spike B.1.617.2, but not in wild-type HEL293T cells.

Tested Applications

Western Blotting Analysis: A representative lot detected SARS-CoV-2 Delta spike protein (P681R) in Various whole cell lysates of HEK293T SARS-CoV-2 spike transfectants (Data courtesy of Dr. Stefan Schüchner and Dr. Egon Ogris (Max Perutz Labs, Medical University of Vienna, Austria).

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user.

Clone 4C5-B2 is a mouse monoclonal antibody that detects the Delta variant of SARS-Cov-2 Spike protein with P681R mutation.

Purified mouse monoclonal antibody IgG2a in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mM NaCl with 0.05% sodium azide.

0.5 mg/mL. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Recommended storage: +2°C to +8°C.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.