Recombinant Biotinylated SARS Spike protein (R667A, K968P, V969P), His, Avitag™ (MALS verified), 25µg

Background
The spike protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion.The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity

Source
Recombinant Biotinylated SARS Spike protein, His,Avitag (SPN-S82E3) is expressed from human 293 cells (HEK293). It contains AA Ser 14 - Pro 1195 (Accession # AAP13567.1(R667A, K968P, V969P)).
Predicted N-terminus: Ser 14

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag (Avitag™).
The protein has a calculated MW of 138.0 kDa. The protein migrates as 160-200 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Biotinylation
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.

Biotin:Protein Ratio
Passed as determined by the HABA assay / binding ELISA.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.

Formulation
Lyophilized from 0.22 μm filtered solution in PBS with trehalose as protectant.

Reconstitution
See Certificate of Analysis for reconstitution instructions and specific concentrations.

Bioactivity
Please refer to product data sheet.

Storage
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
-20°C to -70°C for 12 months in lyophilized state;
-70^°C for 3 months under sterile conditions after reconstitution.

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