| Source: |
Insect Cell |
| Molecular Weight: |
Approximately 52.3 kDa as predicted, containing 465 amino acids. On SDS-PAGE, 54 kDa under reducing conditions, and 101.5 kDa as homodimer under non-reducing conditions. |
| AA Sequence: |
AGMGRVQPTE SIVRFPNITN LCPFGEVFNA TRFASVYAWN RKRISNCVAD YSVLYNSASF STFKCYGVSP TKLNDLCFTN VYADSFVIRG DEVRQIAPGQ TGKIADYNYK LPDDFTGCVI AWNSNNLDSK VGGNYNYLYR LFRKSNLKPF ERDISTEIYQ AGSTPCNGVE GFNCYFPLQS YGFQPTNGVG YQPYRVVVLS FELLHAPATV CGPKKSTNLV KNKCVNFIEG RMDEPKSSDK THTCPPCPAP EFEGAPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPTPI EKTISKAKGQ PREPQVYTLP PSRDELTKNQ VSLTCLVKGF YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGK |
| Purity: |
> 90% by SDS-PAGE. |
| Physical Appearance: |
White lyophilized (freeze-dried) powder. |
| Formulation: |
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH7.0, 5% trehalose. |
| Endotoxin: |
Less than 0.1 EU/μg of rSARS-CoV-2 Spike RBD-Fc as determined by LAL method. |
| Reconstitution: |
We recommend that this vial is briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in PBS to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20°C. Further dilutions should be made in appropriate buffered solutions. |
| 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: |
SARS-CoV-2, which causes COVID-19, is a coronavirus composed of four structural proteins: spike (S), envelope (E), membrane (M), and nucleocapsid (N). The spike protein (S) facilitates viral entry and membrane fusion and is a homotrimeric glycoprotein with each monomer consisting of S1 and S2 subunits. Proteolytic cleavage into S1 and S2 is necessary for activation. S1 attaches to the host receptor, while S2 aids in cell fusion. The receptor-binding domain (RBD) in S1 can be in an "up" or "down" state, with the "up" state linked to higher pathogenicity. The RBD of SARS-CoV-2 has 73% amino acid sequence identity with SARS-CoV-1 but only 22% with MERS, reflecting different receptor bindings. SARS-CoV-2 binds to the ACE2 receptor with higher affinity and faster kinetics than SARS-CoV-1. Structural analysis shows only one RBD domain in the "up" conformation at a time, a target for neutralizing antibody therapy. Polyclonal antibodies against the RBD can inhibit ACE2 interaction, making it a key target for vaccines and antiviral therapy. Additionally, the RBD can help detect neutralizing antibodies in patients. The S protein can also invade host cells via the CD147/EMMPRIN receptor. |
