ACE2 peptide fragment interacts with several sites on the SARS-CoV-2 spike protein S1

Abstract

The influence of the peptide QAKTFLDKFNHEAEDLFYQ on the kinetics of the SARS-CoV-2 spike protein S1 binding to angiotensin-converting enzyme 2(ACE2) was studied to model the interaction of the virus with its host cell. This peptide corresponds to the sequence 24-42 of the ACE2 α1 domain, which is the binding site for the S1 protein. The on-rate and off-rate of S1-ACE2 complex formation were measured in the presence of various peptide concentrations using Bio-Layer Interferometry (BLI). The formation of the S1-ACE2 complex was inhibited when the S1 protein was preincubated with the peptide, however, no significant inhibitory effect was observed in the absence of preincubation. Dissociation kinetics revealed that the peptide remained bound to the S1-ACE2 complex and stabilized this complex. Computational mapping of the S1 protein surface for peptide binding revealed two additional sites, located at some distance from the receptor binding domain (RBD) of S1. These additional binding sites affect the interaction between the peptide, the S1 protein, and ACE2.

Virtual and biochemical screening to identify the inhibitors of binding between SARS-CoV-2 spike protein and human angiotensin-converting enzyme 2

“…The binding assays were performed by Reaction Biology Corp. (Malvern, PA, USA) with SPR technology to measure the direct binding of the potential inhibitors to S-protein. This assay seemed to be suitable for determining whether a test molecule inhibits the S-protein-ACE2 interaction to block the entry of SARS-CoV-2 into the host cells [ 26 ].

Fig.

…”