Synthesis, Mass Spectrometry Characterization, and Inhibition efficacy of Dimeric Peptide Targeting the Main Protease of SARS-CoV-2
Disciplines
Biochemistry | Medicinal-Pharmaceutical Chemistry
Abstract (300 words maximum)
Main protease (Mpro) of SARS-CoV-2 has been identified as an important protein for viral replication. Linear and cyclic peptides have been utilized to block the catalytic dyad of Cys145 and His41 of the Mpro which showed micromolar level inhibition efficiency. However, very few studies are conducted on the dimeric peptides due to the complication in their synthesis. Some of the advantages of peptide dimerization include elevating their antiviral, antimicrobial activity, selectivity, homolytic activity, vesical permeability, and serum stability. Dimer peptides consist of two peptides linked together in one of three ways, sulfur bridging between two cystines, C-terminal linkage using Fmoc-Lys(Fmoc)-OH, and N-terminal linkage using Fmoc-Glu-OH. Our previous studies showed that Temporin L (a peptide from frog skin) and its analogues can effectively inhibit the Mpro with micromolar level efficiency. In this study, dimerization was conducted on two analogues of Temporin L. The synthesis of the peptides utilized automated Fmoc solid-phase synthesis. Peptide products were characterized using mass spectroscopy, ensuring experimental m/z values agreed with theoretical values. Thus far, synthesis of two of the three peptides were confirmed by mass spectrometry which agreed well with the theoretical masses. For the cystine dimerized peptide, peaks detected at m/z 1197.75 and 898.67 correspond to [M+2H]2+ and [M+3H]3+ charge states, respectively with a theoretical mass of 3592.28. For the lysine dimerized peptide, peaks observed at m/z 1505.58 and 758.33 correspond to [M+2H]2+ and [M+3H]3+ charge states with a theoretical mass of 3133.62. The estimated IC50 of the cystine dimerized Temporin analogues obtained from selected ion monitoring based LCMS protease assay was 994.9 nM compared to the IC50 values of 11.4 and 13.4 µM of the monomer peptides. The effectiveness of the other dimerized peptides will be analyzed by fluorescence resonance energy transfer (FRET) and LCMS based assays.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad Halim
Synthesis, Mass Spectrometry Characterization, and Inhibition efficacy of Dimeric Peptide Targeting the Main Protease of SARS-CoV-2
Main protease (Mpro) of SARS-CoV-2 has been identified as an important protein for viral replication. Linear and cyclic peptides have been utilized to block the catalytic dyad of Cys145 and His41 of the Mpro which showed micromolar level inhibition efficiency. However, very few studies are conducted on the dimeric peptides due to the complication in their synthesis. Some of the advantages of peptide dimerization include elevating their antiviral, antimicrobial activity, selectivity, homolytic activity, vesical permeability, and serum stability. Dimer peptides consist of two peptides linked together in one of three ways, sulfur bridging between two cystines, C-terminal linkage using Fmoc-Lys(Fmoc)-OH, and N-terminal linkage using Fmoc-Glu-OH. Our previous studies showed that Temporin L (a peptide from frog skin) and its analogues can effectively inhibit the Mpro with micromolar level efficiency. In this study, dimerization was conducted on two analogues of Temporin L. The synthesis of the peptides utilized automated Fmoc solid-phase synthesis. Peptide products were characterized using mass spectroscopy, ensuring experimental m/z values agreed with theoretical values. Thus far, synthesis of two of the three peptides were confirmed by mass spectrometry which agreed well with the theoretical masses. For the cystine dimerized peptide, peaks detected at m/z 1197.75 and 898.67 correspond to [M+2H]2+ and [M+3H]3+ charge states, respectively with a theoretical mass of 3592.28. For the lysine dimerized peptide, peaks observed at m/z 1505.58 and 758.33 correspond to [M+2H]2+ and [M+3H]3+ charge states with a theoretical mass of 3133.62. The estimated IC50 of the cystine dimerized Temporin analogues obtained from selected ion monitoring based LCMS protease assay was 994.9 nM compared to the IC50 values of 11.4 and 13.4 µM of the monomer peptides. The effectiveness of the other dimerized peptides will be analyzed by fluorescence resonance energy transfer (FRET) and LCMS based assays.