Recombinant protein of the receptor binding domain (RBD), Mutant (L452R) of SARS-CoV-2 (COVID-2019) Spike S1 from Wuhan pneumonia virus with C-terminal GFP/His-Tag. The mutation L452R is characteristic for the SARS-CoV-2 virus variants B.1.427 or B.1.429 emerged in California/USA. These variants are also known as CAL.20C. The mutation is affecting the receptor binding domain (RBD) of the spike protein, which the virus uses to bind to human cells receptors and enter them. Due to the mutation, the virus is allowed to bind with higher affinity to human ACE2 receptor which results in increased transmissibility of the SARS-CoV-2 virus.
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 B.1.427 and the related lineage B.1.429 exhibits 5 mutations in the spike protein. CDC has listed both lineages as “variants of concern”. Compared to the previously circulating variants, the mutations L452R of the SARS-CoV-2 Spike S1 (RBD) may cause a stronger affinity of the spike protein to hACE2 resulting in higher transmission and eventually also in reduced neutralization. The mutation L452R is also found in the variant B.1.617 first detected in India. This variant is also known as G/452R.V3.