Targeting C-terminal Helical bundle of NCOVID19 Envelope (E) protein

Area of Science:

• Virology
• Structural Biology
• Medicinal Chemistry

Background:

• The Envelope (E) protein of SARS-CoV-1 and SARS-CoV-2 is vital for viral replication, assembly, and ion channel activity.
• Structural studies reveal the E protein forms a homopentamer, with key regions including transmembrane domains, glycosylation motifs, and hydrophobic helical bundles.

Purpose of the Study:

• To develop a homology model of the SARS-CoV-2 E protein and identify potential small molecule inhibitors targeting critical functional regions.
• To investigate the role of the glycosylation motif and hydrophobic helical bundle in viral replication.

Main Methods:

• Developed a homology model of the SARS-CoV-2 E protein based on SARS-CoV-1 E protein structure.
• Created a four-feature (4F) pharmacophore model targeting the glycosylation motif and helical bundle.
• Screened a small molecule library using the pharmacophore model, followed by ADMET filtering, molecular docking, and STD NMR binding assays.

Main Results:

• Identified 10 potential drug candidates from ~7000 screened compounds.
• One ligand, 2-(2-amino-2-oxo-ethoxy)-N-benzyl-benzamide, demonstrated binding to the SARS-CoV-2 E protein with a K_D of 141.7 ± 13.6 μM.
• Binding was confirmed to the C-terminal peptide, supporting the involvement of the C-terminal helical bundle.

Conclusions:

• The study successfully identified a small molecule inhibitor targeting the SARS-CoV-2 E protein.
• The findings highlight the potential of targeting the E protein's glycosylation motif and helical bundle for antiviral drug development against COVID-19.