2019 nCoV/COVID19 RBD domain of spike recombinant protein (S)- Fc tag


100 µg


2019 nCoV/COVID19 RBD domain of Spike recombinant protein (S)

The Recombinant 2019-nCoV RBD protein is consisting of 460 amino acid residues. The DNA sequence encoding the COVID-19 RBD protein domain [319-541] of nCOV spike (S) protein, including a C-terminal mouse IgG1 Fc-tag, was expressed in CHO Cells.

Predicted Molecular Mass: 70 kDa
2019-nCov Amino Acids: 319-541 aa (Accession No. 6vsb_A)

Source: DNA sequence encoding the COVID-19 RBD protein domain [319-541] of NCoV spike S protein [accession# 6VSB_A ]including a C-terminal mouse IgG1 tag was expressed in CHO Cells.
Molecular weight: Recombinant 2019-nCoV RBD protein is a protein consisting of 460 amino acid residues ,due to glycosylation migrates as an approximately 70 kDa protein on SDS-PAGE.
Activity: The activity was tested by binding Human ACE2 in functional ELISA assay.
Tag: C-terminal mouse IgG1-Tag
Host: CHO cells
Species: 2019-nCoV, SARS-CoV-2
Purity: >95%, as determined by SDS-PAGE and HPLC.
Endotoxin: Endotoxin content was assayed using a LAL gel clot method. Endotoxin level was found to be less than 0.1 ng/µg (1 EU/µg).
Presentation: Recombinant COVID-19 RBD (Receptor Binding Domain) protein was lyophilized from 0.2 µm filtered 20 mM Tris, 300 mM NaCl, 10 % glycerol, pH 8.0.
Reconstitution: A quick spin of the vial followed by reconstitution in distilled water to a concentration not less than 0.1 mg/mL. This solution can then be diluted into other buffers.
Shipping: The lyophilized protein is shipped at ambient temperature.
Storage: The lyophilized protein is stable for at least 2 years from date of receipt at -20°C.
Usage: This product is for Research Use Only. It may not be used for therapeutics or diagnostic purposes.

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.

The activity was measured by the ability to bind immobilized human ACE2-Fc with a linear range of 1-50 ng/ml.