RBD (N501Y) (319-541) is a recombinant 2019-nCoV Spike protein S1 subunit that is expressed in CHO cells through a C-terminal His tag.
The purity of the protein was found to be roughly 90% by densitometry with a molecular weight of around 39 kDa. The activity is identified by examining the binding ability of the 2019-nCoV Spike protein RBD (N501Y) with the immobilized human ACE2 (19-740) protein utilizing a functional ELISA.
The host ACE2 receptor is recognized by the receptor-binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. The RBD is a significant determinant of the entry and neutralization of viruses.1
B.1.1.7 lineage, a SARS-CoV-2 variant, reported from the United Kingdom has N501Y mutation at one of the six important contact residues in the receptor-binding domain implicated in ACE2 binding.
MD studies denote that the N501Y mutant could raise the stability of the RBD domain with the ACE2 protein and thus lead to a higher virulence when compared to the wild-type strain.2 As the first-wave virus is displaced by new variants, it is crucial to assess their virulence, transmissibility, and their potential tendency to escape antibody neutralization.3
Binding ability measured in a functional ELISA. Compared to 2019-nCoV spike protein RBD (C19SD-G241H), 2019-nCoV spike protein RBD (N501Y) exhibits increased binding potency for immobilized human ACE2 (19-740) protein (A51C2-G341F). Image Credit: SignalChem Biotech Inc.
- Lan J, et al: Crystal structure of the 2019-nCov spike receptor-binding domain bound with the ACE2 receptor. bioRxiv. doi: https://doi.org/10.1101/2020.02.19.956235.
- Sharma T, et al: Unbuttoning the impact of N501Y mutant RBD on viral entry mechanism: A computational insight. bioRxiv 2020; doi: https://doi.org/10.1101/2020.12.30.424906
- Starr TN, et al: Molecular dynamic simulation reveals E484K mutation enhances spike RBD-ACE2 affinity and the combination of E484K, K417N and N501Y mutations (501Y.V2 variant) induces conformational change greater than N501Y mutant alone, potentially resulting in an escape mutant. Cell. 2020, 182(5):1295–1310.