Biotinylated Recombinant SARS-CoV-2 Spike S1-His-Avi Protein

Source: Biotinylated recombinant SARS-CoV-2 Spike S1 protein (Gln14-Arg683) was expressed in mammalian cells with a His tag and Avi at the C-terminus.Accession: QHD43416.1Predicted molecular mass: 77.9 kDa. Due to glycosylation, the biotinylated recombinant SARS-CoV-2 Spike S1 protein migrates to 110-120 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 S1-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 81 ng/ml determined by ELISA.Formulation: The biotinylated recombinant SARS-CoV-2 Spike S1-His-Avi protein 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 spike protein (S) of coronavirus (CoV) attaches the virus to its cellular receptor, angiotensin-converting enzyme 2 (ACE2). A defined receptor-binding domain (RBD) on S mediates this interaction. The S protein plays key parts in the induction of neutralizing-antibody and T-cellresponses, as well as protective immunity.