Synthesis, Characterization and In-Vitro Assay of Staple and Dimer Cationic Peptides Targeting the Main Protease of SARS-CoV-2
Disciplines
Biochemistry | Medicinal-Pharmaceutical Chemistry
Abstract (300 words maximum)
The main protease (Mpro) of SARS-CoV-2 is a critical factor in the virus's ability to replicate, making it a prime target for therapeutic intervention. Research efforts have explored various peptide-based inhibitors aimed at disrupting the activity of Mpro. Our previous published study showed that cationic peptide Indolicidin and its analogues can moderately inhibit (IC50 = 59 micromolar) the main protease of SARS-CoV-2. The aim of this study is to design some non-covalent staple and dimer analogues improving the inhibition efficiency of Indolicidin. We hypothesize that staple and dimeric peptides can show promising results regarding their efficacy in inhibiting Mpro function, thereby hindering viral replication. In the α-methylated Indolicidin variant, methyl groups were introduced to the alpha carbon of two phenylalanine residues which can form pi-pi staple. Dimeric peptides are distinct from pi-pi stapled peptides and are characterized by the interconnection of two peptide chains. Dimer peptides exhibit heightened complexity and interactions owing to the coupling of these peptide chains, contrasting with the stapled peptide, which consist of singular peptide chains. Dimeric structure was achieved through the C-terminal linkage method employing Fmoc-Lys(Fmoc)-OH. Solid-phase peptide synthesis (SPPS) was employed to synthesize the peptides and following the synthesis, the peptide underwent mass spectroscopy characterization to validate its structural integrity and confirm its identity. To determine the 50% inhibitory concentration (IC50) of the peptides, a selected ion monitoring (SIM) based LCMS assay (liquid chromatography-mass spectrometry) was conducted. This approach exhibited the inhibition levels and effectiveness of the synthesized peptides, offering valuable insights into their potential as therapeutic agents against SARS-CoV-2. Results indicated that the dimer exhibited the most potent inhibition, with an IC50 value of 1.90 micromolar (µM), while the α-methylated Indolicidin displayed moderate inhibition efficiency, with an IC50 of 10.75 µM. Overall, exploring dimeric and staple represents a promising avenue for developing novel antiviral therapies with enhanced efficacy and potency.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Synthesis, Characterization and In-Vitro Assay of Staple and Dimer Cationic Peptides Targeting the Main Protease of SARS-CoV-2
The main protease (Mpro) of SARS-CoV-2 is a critical factor in the virus's ability to replicate, making it a prime target for therapeutic intervention. Research efforts have explored various peptide-based inhibitors aimed at disrupting the activity of Mpro. Our previous published study showed that cationic peptide Indolicidin and its analogues can moderately inhibit (IC50 = 59 micromolar) the main protease of SARS-CoV-2. The aim of this study is to design some non-covalent staple and dimer analogues improving the inhibition efficiency of Indolicidin. We hypothesize that staple and dimeric peptides can show promising results regarding their efficacy in inhibiting Mpro function, thereby hindering viral replication. In the α-methylated Indolicidin variant, methyl groups were introduced to the alpha carbon of two phenylalanine residues which can form pi-pi staple. Dimeric peptides are distinct from pi-pi stapled peptides and are characterized by the interconnection of two peptide chains. Dimer peptides exhibit heightened complexity and interactions owing to the coupling of these peptide chains, contrasting with the stapled peptide, which consist of singular peptide chains. Dimeric structure was achieved through the C-terminal linkage method employing Fmoc-Lys(Fmoc)-OH. Solid-phase peptide synthesis (SPPS) was employed to synthesize the peptides and following the synthesis, the peptide underwent mass spectroscopy characterization to validate its structural integrity and confirm its identity. To determine the 50% inhibitory concentration (IC50) of the peptides, a selected ion monitoring (SIM) based LCMS assay (liquid chromatography-mass spectrometry) was conducted. This approach exhibited the inhibition levels and effectiveness of the synthesized peptides, offering valuable insights into their potential as therapeutic agents against SARS-CoV-2. Results indicated that the dimer exhibited the most potent inhibition, with an IC50 value of 1.90 micromolar (µM), while the α-methylated Indolicidin displayed moderate inhibition efficiency, with an IC50 of 10.75 µM. Overall, exploring dimeric and staple represents a promising avenue for developing novel antiviral therapies with enhanced efficacy and potency.