2019 nCoV/COVID19 RBD domain of spike recombinant protein (S), Biotinylated


500 µg


2019 nCoV/COVID10 RBD of Spike Recombinant Protein (S)

The recombinant 2019-nCoV RBD protein is consisting of 250 amino acid residues. DNA sequence encoding the COVID-19 RBD protein domain [319-541] of nCoV S protein, including a C-terminal His AVI tag, was expressed in CHO Cells.

Predicted Molecular Mass: 35 kDa
2019-nCov Amino Acids: 319-541 aa (Accession No. 6vsb_A)

Source: DNA sequence encoding the COVID-19 Spike RBD Protein Domain [319-541] accession #6VSB_A, including a C-terminal His AVI tag, was expressed in CHO Cells.
Molecular weight: The recombinant 2019-nCoV RBD protein is consisting of 250 amino acid residues. Due to glycosylation migrates as an approximately 35kDa protein on SDS-PAGE.
Species 2019-nCoV, SARS-CoV-2
Tag: C-terminal His AVI Tag
Host: CHO Cells
Purity: >95%, as determined by SDS-PAGE and HPLC.
Activity: The activity was determined by immobilized human ACE2 protein binding with biotinylated RBD in a functional ELISA assay, the linear was determined to be 10-100ng/ml.
Endotoxin: Endotoxin content was assayed using a LAL gel clot method. Endotoxin level was found to be less than 0.1 ng/µg(1EU/µg).
Presentation: Recombinant COVID-19 RBD (Receptor Binding Domain) protein was lyophilized from 0.2 µm filtered PBS, pH 7.4.
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.