SARS-CoV-2 Spike S1+S2 trimer Protein (ECD, His & AVI Tag), Biotinylated

The spike (S) glycoprotein of coronaviruses contains protrusions that will only bind to certain receptors on the host cell. Known receptors bind 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 spike 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. The spike (S) glycoprotein of coronaviruses is known to be essential in the binding of the virus to the host cell at the advent of the infection process. It's been reported that SARS-CoV-2 (COVID-19 coronavirus, 2019-nCoV) can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor. The spike 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. The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity. The main functions for the Spike 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.

A DNA sequence encoding the SARS-CoV-2 Spike S1+S2 (YP_009724390.1, with mutations D614G, F817P, A892P, A899P, A942P, K986P, V987P and furin cleavage site mutants) was expressed with bacteriophage T4 fibritin and a C-terminal polyhistidine tagged AVI tag at the C-terminus. The expressed protein was biotinylated in vivo by the Biotin-Protein ligase (BirA enzyme) which is co-expressed.

Immobilized human ACE2 protein (mFc tag) (Cat:PH52212M4) at 2 μg/mL (100 μL/well) can bind SARS-CoV-2 Spike S1+S2 trimer Protein (ECD, His & AVI Tag), Biotinylated (Cat:PO54498M2), the ECis 10-48 ng/mL.

Lyophilized from sterile 25mM sodium citrate, 200mM NaCl, 0.02% Tween 80, pH6.0. Please contact us for any concerns or special requirements. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization. Please refer to the specific buffer information in the hard copy of CoA.

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. Stable for 1 year at -20°C or below from date of shipment. For maximum recovery of product, centrifuge the original vial after thawing and opening the cap. For long-term storage, aliquot and store at -20°C or below. Avoid repeated freeze-thaw cycles.