Synthetic Peptides That Antagonize the Angiotensin-Converting Enzyme-2 (ACE-2) Interaction with SARS-CoV-2 Receptor Binding Spike Protein

Abstract

The SARS-CoV-2 viral spike protein S receptor-binding domain (S-RBD) binds ACE2 on host cells to initiate molecular events, resulting in intracellular release of the viral genome. Therefore, antagonists of this interaction could allow a modality for therapeutic intervention. Peptides can inhibit the S-RBD:ACE2 interaction by interacting with the protein–protein interface. In this study, protein contact atlas data and molecular dynamics simulations were used to locate interaction hotspots on the secondary structure elements α1, α2, α3, β3, and β4 of ACE2. We designed a library of discontinuous peptides based upon a combination of the hotspot interactions, which were synthesized and screened in a bioluminescence-based assay. The peptides demonstrated high efficacy in antagonizing the SARS-CoV-2 S-RBD:ACE2 interaction and were validated by microscale thermophoresis which demonstrated strong binding affinity (∼10 nM) of these peptides to S-RBD. We anticipate that such discontinuous peptides may hold the potential for an efficient therapeutic treatment for COVID-19.

Smaller, Stronger, More Stable: Peptide Variants of a SARS-CoV-2 Neutralizing Miniprotein

“…Furthermore, antibodies are very large molecules, which may hamper tissue penetration, as well as access to sterically shielded epitopes. Therefore, current research is also focused on developing alternative, smaller molecules capable of interfering with the interaction of the SARS-CoV-2 spike protein with cellular ACE2 [ 12 , 13 , 14 , 15 ]. Over the past two years, a range of studies have reported the computational design of smaller proteins or peptides, either based on the structure of the two N-terminal α-helices of ACE2, through which it contacts the receptor binding domain (RBD) of the SARS-CoV-2 spike protein [ 16 , 17 , 18 , 19 ], or through de novo design based on the RBD structure [ 19 , 20 , 21 ].…”

Radical-mediated thiol–ene ‘click’ reactions in deep eutectic solvents for bioconjugation

“…43 This interaction is an essential route of entry for SARS-CoV-2. 44 For demonstration of the use of thiolene chemistry in DESs on an analogue of this peptide, the peptide sequence CEDLFYQ (23) was synthesised by Fmoc-SPPS, wherein the Cys residue replaces an alanine in the sequence of the human protein, and provides the thiol moiety for functionalisation of the peptide without alteration of the minimal sequence required for binding. The optimised UVinitiated conditions were applied to the peptide with excess cyclohexene, as this alkene is commercially available and had shown good yield in both UV-and O 2 -initiated TEC with Boc-Cys-OMe.…”

A Collection of Designed Peptides to Target SARS-CoV-2 Spike RBD—ACE2 Interaction

“…elements of the interface. In the case of RBD/ACE2 interface, different peptides recapitulated the main H1 helix (partially or entirely) with minor conformation adjustments (Figure 3A) Likewise, in the case of the ACE2/ACE2 interface, peptides also show a helical conformation similar to the helix that mediates the interaction between ACE2 monomers (Figure 3B) Redesigned native elements, such as the main H1 helix, has been shown to inhibit the interaction between RBD and ACE2 ( [8,[25][26][27]). Besides recapitulation of native structural elements, designed peptides also presented novel conformations not observed in the native complexes.…”

“…In the context of viral infection examples such as the FDA-approved peptide Enfurvirtide [16] and further research (reviewed in [17,18]) illustrate the use of peptides as potential agents to block PPIs. In fact, a number of recent publications has shown promising results on the use of peptides to blocks the entrance of SARS-CoV-2 virus using peptides derived from native element of the interaction humanACE2 and SARS-CoV-2 spike [19][20][21] including designed peptides targeting of the heptad repeat 1 region [22], the RBD domain [23][24][25], with validation in cell-cultures [26,27] and tissues [28]. While these approaches rely on the sequence diversification of existing native elements, ours complements these efforts by providing novel sequences (next).…”