Recombinant SARS-CoV-2 Spike protein (Val16-Gln1208 ) with furin mutation, and C-terminus trimer motif and His tag was expressed in 293 Cells.
Molecular Weight
This protein has a predicted molecular weight of 138 kDa. Under DTT-reducing conditions, the protein migrates at approximately 150-180 kDa on SDS-PAGE.
Affinity Tag
C-His
Purity
>90% based on SDS-PAGE under reducing condition
Regulatory Status
RUO
Formulation
1xPBS buffer, pH7.4, 0.22 µm filtered
Endotoxin level
Not tested
Protein Concentration
25µg size is bottled at 0.2mg/mL concentration. 100 µg size is supplied at a lot-specific concentration.
Storage and Handling
Briefly centrifuge the vial upon receipt. An unopened vial can be stored at 4°C for up to 2 weeks, or at -20°C or below for up to six months. The protein may be further diluted to 0.1 mg/mL using 0.22 µm-filtered PBS buffer (pH 7.4). For long-term storage, the diluted stock solution should be aliquoted and stored at ≤ –70°C to minimize freeze-thaw cycles. If additional dilution is required, carrier proteins such as FBS or BSA should be added to maintain protein stability.
Background Information
The spike protein forms a homotrimer on the viral surface, with each monomer composed of two functional subunits: S1 and S2. The spike protein is heavily glycosylated, shielding it from host antibodies and contributing to immune evasion. Spike trimer protein mediates the membrane fusion and viral entry. Upon ACE2 engagement and proteolytic cleavage (e.g., by furin or TMPRSS2), the S1 subunit dissociates, and S2 undergoes a conformational change to trigger membrane fusion. The trimeric spike is the main target for neutralizing antibodies and vaccines, making its structural integrity and mutations within it (especially in RBD and S1/S2 cleavage site) critical to viral infectivity, immune escape, and vaccine efficacy.
