SARS-CoV-2 (COVID-19) Spike Variant Recombinant Proteins

Recombinant proteins of SARS-CoV-2 variants

Many SARS-CoV-2 variants are currently spreading across the planet. Since late 2020, three of them have generated concerns about possible enhanced transmissibility and/or increased lethality. These include the so-called UK, South Africa, and Brazil variants. All three combine multiple mutations (~seventeen to twenty-three) at different points in their genomes, with eight to eleven of these alterations occurring in their respective spike proteins (all have D614G). So far, most experts think the present vaccines will still be effective against these three variants, though there is some unease among scientists and physicians about diminished efficacy. As particular interest has focused on the spike mutations, we offer the following images to illustrate their location.

SARS-CoV-2 UK Variant

In late 2020, the United Kingdom reported the B.1.1.7 variant (aka 20I/501Y.V1) that appears to be significantly more transmissible and perhaps more virulent. At this point, it has been identified in at least sixty-two countries. Eight of its twenty-three mutations are in the spike protein, with N501Y in the receptor binding domain (RBD) being of most concern as it may be involved in increased ACE2 affinity.

SARS-CoV-2 South Africa Variant

In January of 2021, the B.1.351 variant (aka 20H/501Y.V2) was found in South Africa. It has twenty-one mutations, with eight being in the spike protein. As with the other two variants, it includes the N501Y mutation but also has two additional RBD mutations (E484K, K417N). It appears to be more transmissible, and the E484K mutation is worrisome as it was shown to reduce antibody recognition. Like the UK variant, it has spread to other countries (at least twenty).

SARS-CoV-2 Brazil Variant

Near the end of January 2021, Japanese authorities reported a new SARS-CoV-2 virus variant obtained from four Brazilian travelers. This variant is designated P.1 (aka 20J/501Y.V3) and has seventeen mutations, with eleven in spike. Some evidence suggests that this variant may also be more transmissible and have some immune escape capability. It carries the same three RBD mutations seen in the South Africa variant, and has been found in other countries.

GeneTex is now developing reagents to support research into these SARS-CoV-2 variants, beginning with recombinant spike proteins that bear many of these key mutations.

Wild-type & Single Mutation Spike Protein

501Y.V1 (UK variant) Spike Proteins

501Y.V2 ( South Africa Variant) Spike Proteins

501Y.V3 (Brazil Variant) Spike Proteins