Recombinant protein of the receptor binding domain (RBD), Mutant (L452Q-F490S) of SARS-CoV-2 (COVID-2019) Spike S1 from Wuhan pneumonia virus with C-terminal His/GFP-Tag. The mutations L452Q-F490S are characteristic for the SARS-CoV-2 virus variant C.37 emerged in South America (Peru) in late 2020. C.37 is classified as Variant of Interest (VOI) and also known as Lambda variant. The mutations are affecting the receptor binding domain (RBD) of the spike protein, which the virus uses to bind to human cells receptors and enter them. The variant may result in an increased transmissibility and viral fitness. The F490S mutation together with other mutations at position L452, has been associated with resistance to neutralization.
The spike (S) glycoprotein of coronaviruses is essential for binding of the virus to the host cell at the beginning of the infection process. The target protein is also a major immunogen and a possible target for entry inhibitors. The SARS-CoV-2 spike (S) protein is a large type I transmembrane protein composed of two subunits, S1 and S2. The S1 subunit contains a receptor-binding domain (RBD) responsible for binding to the host cell receptor angiotensin-converting enzyme 2 (ACE2). Several mutants of the spike protein are known. A new SARS-CoV-2 lineage called C.37 or Lambda variant, exhibits 7 mutations in the spike protein. Compared to the other circulating variants, the mutations L452Q and F490S of the SARS-CoV-2 Spike S1 (RBD) are known to make the virus more resistant to neutralizing antibodies and therefore may also have an influence on the effectiveness of existing vaccines. The Lambda variant is classified by the World Health Organization (WHO) as Variant of Interest (VOI).