Anti-SARS-CoV-2 Antibody CR3022 Binds to Coronavirus Variants

Although SARS-CoV-2 is a relatively stable virus, at the end of 2020 a few prominent mutant strains of the novel coronavirus were identified in various human populations (Galloway et al., 2021). Many of the mutations have occurred in the spike protein and its receptor binding domain (RBD), which is responsible for binding ACE2 protein in various human tissues. The appearance of the mutants cast shadow on the diagnostics, therapeutics and vaccines recently released or under development. In the antibody sector, it brought significant uncertainty regarding the efficacy of current anti-coronavirus antibodies and their ability to detect the new variants. Because many of the novel variants seem to be more infectious, spread more quickly among humans, and possibly might be more lethal (Kow and Hasan, 2021), the ability to provide research and diagnostic antibodies able to recognize the new SARS-CoV-2 mutants is more pressing than ever.

At Absolute Antibody, we are keeping an eye on the current developments and have started testing our anti-coronavirus antibodies with various mutant SARS-CoV-2 spike proteins. We are pleased to announce that one of our the most popular clones, CR3022, exhibits excellent binding affinity to all mutants tested, among them two of the most prominent variants, UK (B.1.1.7) and South African (B.1.351 (501Y.V2)) (Arif, 2021) (See Figure 1 and Figure 2).

The anti-SARS clone CR3022 was shown in early 2020 to have high affinity for the SARS-CoV-2 virus, and scientists worldwide have used the antibody to evaluate mono- and combination-therapy potential and for serological controls in COVID-19 diagnostic assays. The CR3022 antibody is available in our catalog in a wide variety of engineered formats, designed to open up new experiment possibilities for in vitro and in vivo use. Some of the formats include:

  • Human IgG1, IgG2, IgG3, IgG4, IgA, IgM and IgE for use in neutralization assays and as serological controls
  • Rabbit, mouse, cat and ferret formats for detection applications, co-labeling studies and animal model research
  • Human and mouse Fab and Fab2 formats with His-tags, for applications where antibody fragments are desirable and for site-specific functionalization
  • Human IgG1 and mouse IgG2b Fc Silent™ formats, which are aimed at discerning Fc-dependent and Fc-independent effector functions and facilitating research into the role of antibody-dependent enhancement (ADE)
  • ISOblend™ standard, which contains human IgG1, IgG3, IgM and IgA formats formulated at equal amounts for use as a control or calibrator in COVID-19 diagnostic tests

Learn more about each antibody format here or contact us if you are looking for the CR3022 clone in a different format. You can also find our full collection of anti-coronavirus antibodies on our website here.

 

Binding of the antibody CR3022 (Ab01680) to the UK and South African mutant SARS-CoV-2 spike proteins

Figure 1. ELISA using CR3022 (Ab01680) with UK (B.1.1.7) and South African (B.1.351 (501Y.V2)) mutant spike proteins. The plate was coated with the mutant spike protein variants (The Native Antigen Company) at 2.5 µg/ml. Ab01680 was conjugated to HRP and titrated on a 3-fold serial dilution starting at 1,000 ng/ml. CR3022 (Ab01680) exhibited exceptional binding to all mutant spike proteins. WT – wild type.

 

Binding of the antibody CR3022 (Ab01680) to other mutant SARS-CoV-2 spike proteins

Figure 2. ELISA using CR3022 (Ab01680) and mutant spike proteins. The plate was coated with the mutant spike protein variants (The Native Antigen Company) at 2.5 µg/ml. Ab01680 was conjugated to HRP and titrated on a 3-fold serial dilution starting at 1,000 ng/ml. CR3022 (Ab01680) exhibited exceptional binding to all mutant spike proteins. RBD WT – wild-type receptor binding domain.