Recombinant Biotinylated HCoV-HKU1 (isolate N5) Spike Trimer, His,Avitag™ (MALS verified), 25µg

Background
It's been reported that SARS-CoV-2 can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor. 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 HCoV-HKU1 (isolate N5) Spike Trimer, His,Avitag (SPN-H82E3) is expressed from human 293 cells (HEK293). It contains AA Ala 13 - Asn 1276 (Accession # Q0ZME7-1). Amino acid substitutions RRKRR 752-756 GGSGS and NL 1067-1068 PP are introduced to abolish the furin cleavage site and stabilize the trimeric prefusion state of the spike protein, respectively.
Predicted N-terminus: Ala 13

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag.
The protein has a calculated MW of 147.2 kDa. The protein migrates as 200-220 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.

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

Reconstitution
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

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.

Bioactivity
Please refer to product data sheet.

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