SARS-CoV-2 (2019-nCoV) Spike Protein (S1+S2 ECD, His tag) (100 μg)

Purity: >90 % as determined by SDS-PAGE.
Tag: His-tag at the C-terminus.
Endotoxin: <1.0 EU per μg protein as determined by the LAL method.
Activity: The 2019-nCoV Spike Protein (S1+S2 ECD, His tag) can bind with Human ACE2 in functional ELISA assay.
Protein Construction: A DNA sequence encoding the NCP-CoV(2019-nCoV) Spike Protein (S1+S2 ECD) was expressed with a polyhistidine tag at the C-terminus.
Expressed Host: Baculovirus-Insect Cells
Species: 2019-nCoV
Predicted N Terminal: Val
Predicted Molecular Mass: The recombinant SARS-CoV-2 (2019-nCoV) S Protein (S1+S2 ECD) consists of 1209 amino acids and predicts a molecular mass of 134.36 kDa.
Formulation: Lyophilized from sterile 20 mM Tris, 300 mM NaCl, 10 % glycerol, pH 8.0. Normally 5 % – 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization.
Shipping: In general, recombinant proteins are provided as lyophilized powder which are shipped at ambient temperature.
Bulk packages of recombinant proteins are provided as frozen liquid. They are shipped out with blue ice unless customers require otherwise.
Storage: Samples are stable for up to twelve months from date of receipt at -20°C to -80°C, under sterile conditions. It is recommended that the protein be aliquoted for optimal storage. Repeated freeze/thaw cycles should be avoided.
Regulatory/Restrictions: For Research Use Only.

SARS-CoV-2 (2019-nCoV) Spike Protein (S1+S2 ECD, His tag) Datasheet

The spike (S) glycoprotein of coronaviruses contains protrusions that will only bind to certain receptors on the host cell. It has been reported that 2019-nCoV can infect the human Respiratory Epithelial cells through interaction with the human ACE2 receptor. The S protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion. So, S protein has a key role in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity.

Known receptors binding S1 are ACE2, Angiotensin-Converting Enzyme 2; DPP4, Dipeptidyl Peptidase-4; APN, Aminopeptidase N; CEACAM, Carcinoembryonic antigen-related cell adhesion molecule 1; Sia, Sialic acid; O-ac Sia, O-acetylated Sialic acid.

The S protein is essential for both host specificity and viral infectivity. The term ‘peplomer’ is typically used to refer to a grouping of heterologous proteins on the virus surface that function together. Besides, the S protein is known to be essential in the binding of the virus to the host cell at the advent of the infection process.

The main functions for the S protein are summarized as:
Mediate receptor binding and membrane fusion; Defines the range of the hosts and specificity of the virus; Main component to bind with the neutralizing antibody; Key target for vaccine design; Can be transmitted between different hosts through gene recombination or mutation of the receptor binding domain (RBD), leading to a higher mortality rate.