Anti-SARS-CoV-2 Spike S2 Polyclonal Antibody for WB, IP, ELISA - P0DTC2

Core Product Specifications and Parameters

Biological Background: Spike Glycoprotein (S2 Subunit) Function and Localization

• The spike glycoprotein (S) is a class I viral fusion protein and the major surface antigen of SARS-CoV-2. It mediates initial attachment to host cells via binding of the receptor-binding domain (RBD) in the S1 subunit to the angiotensin-converting enzyme 2 (ACE2) receptor. Related references: PMID:32142651, PMID:32155444, PMID:33607086
• After receptor binding, the S protein is proteolytically cleaved at the S2′ site by host proteases such as transmembrane protease serine 2 (TMPRSS2) or cathepsin L, triggering conformational rearrangements in the S2 subunit that drive fusion of the viral envelope with the host cell membrane. Related references: PMID:32142651, PMID:32703818, PMID:34159616, PMID:34561887
• The virus can also employ alternative entry receptors, including neuropilin-1 (NRP1) and neuropilin-2 (NRP2), which are highly expressed in olfactory epithelial cells and may explain anosmia symptoms; integrins; and the asialoglycoprotein receptor 1 (ASGR1) in an ACE2-independent manner. Related references: PMID:33082294, PMID:33082293, PMID:35150743, PMID:34837059
• Subcellular localization: The S protein is present on the virion membrane and traffics through the host endoplasmic reticulum–Golgi intermediate compartment (ERGIC) membrane; fusion occurs at the host cell membrane or within endosomes.
• Post-translational modifications include extensive N-linked glycosylation, disulfide bonds, palmitoylation, and cleavage into S1 and S2 subunits. Keywords from UniProt: viral envelope protein, transmembrane, glycoprotein, host–virus interaction, viral immunoevasion, superantigen, and inhibition of host innate immunity.
• The stalk domain of the S protein contains three flexible hinges that permit considerable orientational freedom of the receptor-binding head, a feature critical for immune evasion and receptor engagement. Related references: PMID:32817270

Experimental Guidance and Technical Tips

• The immunogen is a synthetic peptide spanning amino acids 1174–1273 of the S2 subunit (based on reference sequence YP_009724390.1). The antibody is expected to recognize both the full-length spike protein (~141 kDa) and the S2 cleavage fragment.
• For Western blotting, use reducing SDS-PAGE conditions. A band corresponding to the full-length spike at approximately 141 kDa should be observed; low-molecular-weight bands representing S2 cleavage products may also appear. Under non-reducing conditions, higher-order oligomers (trimers) can be detected.
• Include appropriate positive controls, such as lysates from SARS-CoV-2-infected cells or recombinant spike protein. A loading control (e.g., GAPDH, β-actin) is recommended.
• For immunoprecipitation, consider using protein A/G beads pre-coupled with the antibody to minimize detection of heavy-chain bands.
• In ELISA, this polyclonal antibody can serve as a capture or detection reagent in sandwich assays for spike protein quantification. Optimize coating concentrations and blocking buffers for your specific plate format.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio provides diagnostic manufacturers and research institutions with streamlined access to validated IVD raw materials. This anti-SARS-CoV-2 Spike S2 antibody is part of our growing portfolio of COVID-19 research reagents, and we can additionally source matched antibody pairs, bulk monoclonal/polyclonal antibodies, ancillary proteins, and rare-target materials—all supported by technical consultation to bridge your diagnostic development from concept to clinic.