Biotinylated Recombinant SARS-CoV-2 Spike RBD-His-Avi

Source: Biotinylated recombinant SARS-CoV-2 Spike RBD (Arg319-Asn532) was expressed in mammalian cells with a His tag and Avi at the C-terminus.Accession: QHD43416.1Predicted molecular mass: 27 kDa. Due to glycosylation, the recombinant SARS-CoV-2 Spike RBD migrates to 36-40 kDa based on the Bis-Tris PAGE result.Endotoxin: Less than 1 EU per ug by the LAL method.Activity: Immobilized biotinylated recombinant SARS-CoV-2 Spike RBD-His-Avi protein at 1 ug/ml (100 ul/well). Dose response curve for the recombinant human ACE2-Fc fusion protein with the EC50 of 100 ng/ml determined by ELISA.Formulation: The biotinylated recombinant SARS-CoV-2 Spike RBD-His-Avi was lyophilized from 0.22 um filtered solution in 20 mM PB (pH 7.4). Normally 5% trehalose is added as protectant before lyophilization.Purity: > 95% by PAGE under reduced condition, and SEC-HPLC.Shipping: The product is shipped with ice packs. Upon receipt, store it immediately at the temperature recommended below.Stability & Storage:Use a manual defrost freezer and avoid repeated freeze-thaw cycles.12 months from date of receipt, -20 to -70°C as supplied.1 month, 2 to 8°C under sterile conditions after reconstitution.3 months, -20 to -70°C under sterile conditions after reconstitution.

Background

The receptor binding domain (RBD) in the S1 subunit of the SARS-CoV-2 spike (S) glycoprotein plays the most important roles in viral attachment, fusion and entry, and serves as a target for development of virus entry inhibitors, neutralizing antibodies, and vaccines. There are two subunits, S1 and S2, in the SARS-CoV-2 spike (S) glycoprotein. The S1 subunit, the N-terminal 14–685 amino acids of S protein, contains N-terminal domain (NTD), receptor binding domain (RBD), and receptor binding motif (RBM). The SARS-CoV and SARS-CoV-2 S proteins mediate viral entry into host cells by binding to a host receptor, angiotensin-converting enzyme 2 (ACE2), through the receptor-binding domain (RBD), and then fusing the viral and host membranes through the S2 subunit. The ACE2-binding affinity of the Spike RBD of SARS-CoV-2 is 10- to 20-fold higher than that of SARS-CoV.

Both His-tagged and Fc-fused recombinant SARS-CoV-2 S1 RBD are available with an Avi site, which is for biotinylation. Please ask for a quote if you need protein mutants or a protein with different modification or components.