"Plot of surface biolayer amplitude measurement as a function of ACE2 concentration with the data for S from SARS-CoV-2 (blue, Kd calculated as 91 ± 18 nM) and from the bat virus (red, Kd estimated to be >40 μM). Kd for the SARS-CoV-2 protein was calculated from kinetic constants (koff = 0.0105 s−1 and kon = 1.56 × 105 m−1 s−1) and was 67.5 ± 9 nM."

University of Michigan - Ann Arbor

Amplitude analysis provides evidence that SARS-CoV-2 binds more tightly to human ACE2 than the bat virus protein does by around 1,000 times. 

Bat virus RaTG13 and SARS-CoV-2 S glycoprotein affinities to human receptor ACE2

Wrobel, A.G., Benton, D.J., Xu, P. et al. SARS-CoV-2 and bat RaTG13 spike glycoprotein structures inform on virus evolution and furin-cleavage effects. Nat Struct Mol Biol (2020). https://doi.org/10.1038/s41594-020-0468-7

SARS-CoV-2 and bat RaTG13 spike glycoprotein structures inform on virus evolution and furin-cleavage effects

Differences in potential binding interactions were found between ACE2 domain and RBD domain of SARS-CoV-2 and RaTG13 S trimers. SARS-CoV-2 has Phe486 interacting with ACE2 human receptor while the bat virus has Leu486 instead, which is less bulky. SARS-CoV-2 also has a Gln493 that is able to form a hydrogen bond of Glu35 in ACE2, while RaTG13 has a tyrosine that is unlikely to bond with Glu35. More differences are shown in Fig 3b and Fig 3c. These distinctions may impact the differences in S glycoprotein affinity to ACE2 between SARS-CoV-2 and RaTG13. 

Learn Before

Related