Noncovalent Antiviral Peptide Stapling Targeting Main Protease of SARS-CoV-2
Disciplines
Biochemistry | Medicinal-Pharmaceutical Chemistry
Abstract (300 words maximum)
The recent coronavirus pandemic caused by SARS coronavirus 2 (SARS-CoV-2) continues to pose a significant health risk with over 2000 deaths in January 2025 alone. SARS-CoV-2 is an RNA virus comprising 16 nonstructural proteins, 4 structural proteins, and 9 accessory proteins. The nonstructural proteins are cleaved by the main protease (Mpro) of SARS-CoV-2, and the resulting fragments become centers for virus replication and transcription. Thus, inhibiting the Mpro prevents replication, enabling effective prevention and treatment of SARS-CoV-2. In this study peptide therapeutics are used to inhibit the Mpro due to their targeted binding ability to the catalytic dyad His41 and Cys145 with few off target effects. We synthesized two peptides and corresponding noncovalent staple peptide analogues to inhibit the Mpro. These peptides, identified for their high binding affinity in previous bioinformatics studies, are non-cytotoxic and exhibit potent antiviral properties. The corresponding analogues utilize non-covalent peptide stapling by inserting or replacing specific amino acids with an α-methyl-L-phenylalanine. The methyl group on the alpha-carbon helps limit the mobility of amino acids forcing the sidechain interactions between aromatic rings. These extra interactions commonly induce a helical structure providing external stability to the peptide. Efficacy of the peptides are characterized using a selected ion monitoring based LCMS (liquid chromatography coupled with mass spectrometry) assay yielding an inhibition concentration at 50% (IC50). Additionally FRET analysis of the peptides will be performed to yield a second IC50 for comparison. The current data suggests that the non-covalent stapled peptides more selectively target the Mpro compared to their linear counterparts.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad Halim
Noncovalent Antiviral Peptide Stapling Targeting Main Protease of SARS-CoV-2
The recent coronavirus pandemic caused by SARS coronavirus 2 (SARS-CoV-2) continues to pose a significant health risk with over 2000 deaths in January 2025 alone. SARS-CoV-2 is an RNA virus comprising 16 nonstructural proteins, 4 structural proteins, and 9 accessory proteins. The nonstructural proteins are cleaved by the main protease (Mpro) of SARS-CoV-2, and the resulting fragments become centers for virus replication and transcription. Thus, inhibiting the Mpro prevents replication, enabling effective prevention and treatment of SARS-CoV-2. In this study peptide therapeutics are used to inhibit the Mpro due to their targeted binding ability to the catalytic dyad His41 and Cys145 with few off target effects. We synthesized two peptides and corresponding noncovalent staple peptide analogues to inhibit the Mpro. These peptides, identified for their high binding affinity in previous bioinformatics studies, are non-cytotoxic and exhibit potent antiviral properties. The corresponding analogues utilize non-covalent peptide stapling by inserting or replacing specific amino acids with an α-methyl-L-phenylalanine. The methyl group on the alpha-carbon helps limit the mobility of amino acids forcing the sidechain interactions between aromatic rings. These extra interactions commonly induce a helical structure providing external stability to the peptide. Efficacy of the peptides are characterized using a selected ion monitoring based LCMS (liquid chromatography coupled with mass spectrometry) assay yielding an inhibition concentration at 50% (IC50). Additionally FRET analysis of the peptides will be performed to yield a second IC50 for comparison. The current data suggests that the non-covalent stapled peptides more selectively target the Mpro compared to their linear counterparts.