SARS-CoV-2 (2019-nCoV) S protein RBD, mFc-His Tag
New product release: SARS-CoV-2 functional proteins
Time：2020-07-15
A group of Chinese scientists from the Institute of Microbiology at Chinese Academy of Sciences (CAS) recently published their new discovery on the identification of a human neutralizing antibody CB6 clone targeting the ACE2 receptor binding site of SARS-CoV-2. In this study published in Nature magazine, the group isolated and identified two neutralizing antibodies, named as CB6 and CA1 clones, from COVID-19 recovered patients. Among them, CB6 clone exhibits the strongest virus-preventive and protective effect in rhesus monkey infection model. At present, Chinese FDA has officially approved the clinical trial in China for CB6 (JS016) therapeutic antibody drug. In the meantime, TopAlliance and Eli Lily also signed a co-development agreement on CB6 (JS016) in US market. CR3022 is another neutralizing antibody against SARS-CoV virus previously isolated from a convalescent SARS patient. CR3022 clone can bind to an epitope conserved between SARS-CoV-2 and SARS-CoV that is distinct from the receptor-binding site. Therefore, CR3022 does not show any protective effect against SARS-CoV-2 virus. However, it is a commonly used reagent for scientists to study SARS-CoV-2 and SARS-CoV.
Figure 1. CB6 can block SARS-CoV2-RBD binding to hACE2 in FACS-based assay
(图片来源：Nature)
Currently, there are two main categories of COVID-19 diagnostic tests, including –QPCR based molecular test and immunological test. For immunological tests, different SARS-CoV-2 virus proteins, based on the choices of diagnostic kit manufacturers, are used to detect whether patient sera contain anti-virus antibodies. The quality of virus protein used for kit production is critical for the sensitivity and specificity of the test. In DIMA BIOTECH, we are proudly offering SARS-CoV-2 S and N proteins in high quality standard. Our SAR-CoV-2 S proteins were produced by using HEK293 mammalian expression system, which can best mimic the authentic post-translational modifications happened in human cells. To ensure the recombinant S protein inherits the native structure and function of virus counterpart, we not only performed ELISA binding assays to check its interaction with SARS-CoV-2 cellular receptor protein ACE2, but also tested the binding assays with two neutralizing human monoclonal antibodies, CB6 and CR3022 (See the following assay data).
CB6 antibody can efficiently block the binding between SARS-CoV-2 S protein RBD domain with Human ACE2 protein.
Figure 2. ELISA plate coated with recombinant SARA-CoV-2 S protein RBD was first pre-blocked with recombinant CB6 antibody or recombinant CR3022 antibody, and then 100 ng/ml Human ACE2, mFc tagged protein (PME100072) was added to check the competitive inhibition of recombinant CB6 antibody and recombinant CR3022 antibody. This data indicated that recombinant CB6 antibody can efficiently block the binding between SARS-CoV-2 S protein RBD domain with Human ACE2 protein.
To help our customers quickly evaluate the bioactivity of our SARS-CoV-2 S protein products, we include two small packages of CB6 and CR3022 monoclonal antibodies as free sample kit if you order the standard 100 ug or above package.
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Catalog Number: PME100460
Expression Host: HEK293
Tag: C-Mouse Fc and 6×His tag
Purity: Greater than 95% as determined by SDS-PAGE and Coomassie blue staining.
Figure 3. SARS-CoV-2 (2019-nCoV) S protein RBD, mFc-His Tag on SDS-PAGE under reducing condition.
Figure 4. ELISA plate pre-coated by 2 μg/ml (100 μl/well) SARS-CoV-2 (2019-nCoV) S protein RBD, mFc-His tagged protein (PME100460) can bind Anti-SARS-CoV-2 S protein RBD Neutralizing Antibody (A neutralizing monoclonal antibody clone currently under clinical investigation from collaboration company) in a linear range of 0.24-9.141 ng/ml.
Human ACE2 Protein, mFc Tag
Catalog Number: PME100072
Expression Host: HEK293
Tag: C-Mouse Fc tag
Purity: Greater than 95% as determined by SDS-PAGE and Coomassie blue staining.
Figure5.Human ACE2 Protein, mFc Tag on SDS-PAGE under reducing condition.
SARS-CoV-2 (2019-nCoV) Nucleocapsid Protein, His Tag
Catalog Number: PME100459
Expression Host: E.coli
Tag: C-His tag
Purity: Greater than 95% as determined by SDS-PAGE and Coomassie blue staining.
Figure 6. SARS-CoV-2 (2019-nCoV) Nucleocapsid Protein, His Tag on SDS-PAGE under reducing condition.
DIMA Biotechnology LTD is a research and development company focusing on using its proprietary DimAb™ technology platform to develop recombinant monoclonal antibodies. DIMA’s proprietary B cell cloning and recombinant monoclonal antibody development platform, DimAb™, can efficiently generate high-quality monoclonal antibodies in high throughput. The R&D team has many years of experience in monoclonal antibody development. We provide solutions for scientific research, clinical diagnosis and therapeutic R&D. At DIMA, our scientists are working diligently to develop new neutralizing antibodies for SARS-CoV-2. Please stay tuned, we will inform you more exciting progresses on our new DimAb projects.
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Email: dma@dimabio.com