SEC-MALS Validated SARS-CoV-2 Prefusion Trimeric Spike Variant Proteins

The spike protein (S-protein) of SARS-CoV-2 is the most critical target for neutralizing antibody therapeutics generation and vaccine developments. Spike protein is divided into two structural subunits, namely S1 and S2, based on their unique functionalities. S1 is a heavily glycosylated region that harbors the receptor binding domain (RBD), which is responsible for host cell recognition and interaction. Meanwhile, the S2 subunit contains important conformational elements requited for membrane fusion.

The spike protein resides on the surface of SARS-CoV-2 virions in a trimeric conformation (also known as the pre-fusion format). Upon interaction with host cell ACE2 receptor, the S1 subunit is cleaved by host cell proteases (e.g. TMPRSS2) and removed from the S protein to yield the post-fusion format that allows conformational rearrangements in the S2 region, subsequently leads to membrane fusion.

In February 2020, researchers from NIH and the University of Texas announced a cryo-EM structure of trimeric spike protein for the first time, which revealed the dynamics of conformational changes of RBD upon ACE2 interaction. Subsequently, David Veesler's research team from the University of Washington discovered the presence of multiple conformations of the S protein trimer. Upon evaluation of the information on the structure, conformation and distribution of S trimer on the surface of virion, researchers concluded that the pre-fusion format of spike timer is the predominate form on the virion surface, which counts for 97% of the total spike proteins, while the remainder are in the post-fusion status. Subsequent evidence indicated that the pre-fusion Spike trimer is relatively unstable, rendering its manufacturing difficult. Thus, it is essential to develop a stable pre-fusion spike protein trimer to support the development of vaccines, therapeutic antibodies, and diagnostic reagents.

Sino Biological has successfully developed a series of highly stable trimeric spike proteins, covering multiple VOIs or VOCs, such as Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617. 2), Kappa (B.1.617.1), etc. Their purity, oligomeric status, and activity were validated by SDS-PAGE, SEC-MALS and ELISA, respectively, while the protein thermo-stability was validated by freeze-thaw experiments.

  • SARS-CoV-2 Spike (D614G) Trimer (ECD, His tag) (Cat: 40589-V08H8)

    SEC-MALS Validated

    The purity of SARS-CoV-2 Spike Trimer,His Tag (Cat. 40589-V08H8) was more than 90% and the molecular weight of this protein is around 400-540kDa verified by SEC-MALS.

    ACE2 Binding (ELISA)
     
    SDS-PAGE

    Immobilized human ACE2 protein (mFc tag) (Cat:10108-H05H) at 2 μg/mL (100 μL/well) can bind spike trimer (Cat:40589-V08H8), the EC50 is 4-24 ng/mL.

    Purity: > 90 %

  • SARS-CoV-2 B.1.617.2 Spike Trimer (ECD, His tag) (Cat: 40589-V08H10)

    SEC-MALS Validated

    The purity of SARS-CoV-2 Spike Trimer, His Tag (Cat. 40589-V08H10) was more than 90% and the molecular weight of this protein is around 420-520kDa verified by SEC-MALS.

    ACE2 Binding (ELISA)
     
    SDS-PAGE

    Immobilized human ACE2 protein (mFc tag) (Cat:10108-H05H) at 2 μg/mL (100 μL/well) can bind spike trimer (Cat:40589-V08H10), the EC50 is 4-24 ng/mL.

    Purity: > 90 %

More SARS-CoV-2 Prefusion Trimeric Spike Variant Proteins

Cat# WHO Label Prodcut Name Mutations
40589-V08H10 Delta SARS-CoV-2 B.1.617.2 Spike S1+S2 trimer Protein (ECD, His tag) T19R, E156G, 157Del, 158Del, L452R, T478K, D614G, D950N, F817P, A892P, A899P, A942P, K986P, V987P and furin cleavage site mutants
40589-V08H11 Kappa  SARS-CoV-2 B.1.617.1 Spike S1+S2 trimer Protein (ECD, His tag) G142D, E154K, L452R, E484Q, D614G, F817P, A892P, A899P, A942P, K986P, V987P, Q1070H, H1101D and furin cleavage site mutants
40589-V08H12 Alpha SARS-CoV-2 B.1.1.7 Spike S1+S2 trimer Protein (ECD, His tag) (69-70, 145 deletion), N501Y, A570D, D614G, T716I, F817P, A892P, A899P, A942P, S982A, K986P, V987P, D1118H and furin cleavage site mutants
40589-V08H13 Beta SARS-CoV-2 B.1.351 Spike S1+S2 trimer Protein (ECD, His tag) L18F, D80A, D215G, 241-243 deletion, R246I, K417N, E484K, N501Y, D614G, A701V, F817P, A892P, A899P, A942P, K986P, V987P and furin cleavage site mutants
40589-V08H8   SARS-CoV-2 Spike S1+S2 (D614G) trimer Protein (ECD, His tag) D614G, F817P, A892P, A899P, A942P, K986P, V987P and furin cleavage site mutants
40589-V08H9   SARS-CoV-2 B.1.618 Spike S1+S2 trimer Protein (ECD, His tag) H49Y, 145-146 deletion, E484K, D614G, F817P, A892P, A899P, A942P, K986P, V987P and furin cleavage site mutants