Recombinant Spike Protein Trimer: more powerful than you think
S protein is the main target for neutralizing antibodies after infection and has attracted much attention in the development of COVID-19 vaccines and therapeutic antibodies.
Considering the importance of S protein, it is going to be the key to get the stable and uniform trimeric S protein reagent for the development of vaccines, therapeutic antibodies, or serological test kits. After abundant work, scientists found that 2 proline mutations (S-2P) of the S2 subunit stabilize the S protein conformation, most of which will stay at prefusion state. We will walk you through a few different scenarios that recombinant spike trimer protein could help in the following part.
ACROBiosystems has specially designed a super stable S trimer protein. This is the only verified trimeric S protein on the market. Our SEC-MALS and negative-stain EM data reveal that ACRO’s S protein is in the correct trimer form under physiological conditions, and purity is over 90%. The ELISA data shows that the S trimer protein binds to human ACE-2 protein and anti-SARS-CoV-2 neutralizing antibody well.
>> The purity, molecular weight and polymeric form were rigorously verified by SDS-PAGE, SEC-MALS and NS-EM.
Fig 1. The purity of SARS-CoV-2 S protein, His Tag, Super stable trimer (MALS & NS-EM verified) (Cat. No. SPN-C52H9) was more than 90% verified by SDS-PAGE under reducing (R) condition. The molecular weight was around 550-660 kDa confirmed by SEC-MALS. The particles are similar in size and appearance to SARS-CoV-2 trimers reported in published literature verified by negative stain electron micrography.
>> Bioactivities of binding to ACE2 protein and anti-SARS-CoV-2 neutralizing antibody were verified by ELISA
Fig 2. Immobilized Human ACE2, Fc Tag (Cat. No. AC2-H5257) at 2 μg/mL (100 μL/well) can bind SARS-CoV-2 S protein, His Tag, Super stable trimer (MALS & NS-EM verified) (Cat. No. SPN-C52H9) with a linear range of 0.5-16 ng/mL.
|Fig 3. Immobilized Anti-SARS-CoV-2 Neutralizing Antibody, Human IgG1 (Cat. No. SAD-S35) at 1 μg/mL (100 μL/well) can bind SARS-CoV-2 S protein, His Tag, Super stable trimer (Cat. No. SPN-C52H9) with a linear range of 0.5-16 ng/mL.|