Enhanced Binding of SARS-CoV-2 Spike Protein to Receptor by Distal Polybasic Cleavage Sites

Journal Article · Sun Aug 02 00:00:00 EDT 2020 · ACS Nano

DOI:https://doi.org/10.1021/acsnano.0c04798· OSTI ID:1800585

Qiao, Baofu ^[1]; Olvera de la Cruz, Monica ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein plays a crucial role in binding the human cell receptor ACE2 that is required for viral entry. Many studies have been conducted to target the structures of RBD–ACE2 binding and to design RBD-targeting vaccines and drugs. Nevertheless, mutations distal from the SARS-CoV-2 RBD also impact its transmissibility and antibody can target non-RBD regions, suggesting the incomplete role of the RBD region in the spike protein–ACE2 binding. Here, in order to elucidate distant binding mechanisms, we analyze complexes of ACE2 with the wild-type spike protein and with key mutants via large-scale all-atom explicit solvent molecular dynamics simulations. We find that though distributed approximately 10 nm away from the RBD, the SARS-CoV-2 polybasic cleavage sites enhance, via electrostatic interactions and hydration, the RBD–ACE2 binding affinity. A negatively charged tetrapeptide (GluGluLeuGlu) is then designed to neutralize the positively charged arginine on the polybasic cleavage sites. We find that the tetrapeptide GluGluLeuGlu binds to one of the three polybasic cleavage sites of the SARS-CoV-2 spike protein lessening by 34% the RBD–ACE2 binding strength. This significant binding energy reduction demonstrates the feasibility to neutralize RBD–ACE2 binding by targeting this specific polybasic cleavage site. Our work enhances understanding of the binding mechanism of SARS-CoV-2 to ACE2, which may aid the design of therapeutics for COVID-19 infection.

• Research Organization: Northwestern Univ., Evanston, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: FG02-08ER46539
• OSTI ID: 1800585
• Journal Information: ACS Nano, Journal Name: ACS Nano Journal Issue: 8 Vol. 14; ISSN 1936-0851
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
COVID-19
SARS-CoV-2
chemistry
materials science
molecular dynamics simulations
peptide inhibitor
polybasic cleavage sites