A peptide derived from hepatitis C virus E2 envelope protein inhibits a post-binding step in HCV entry

Area of Science:

• Virology
• Molecular Biology
• Drug Discovery

Background:

• Hepatitis C virus (HCV) entry relies on envelope proteins E1 and E2 for cellular receptor binding and membrane fusion.
• Understanding the specific roles of E1 and E2 domains in HCV entry is vital for developing antiviral strategies.

Purpose of the Study:

• To pinpoint critical regions within HCV envelope proteins E1 and E2 involved in viral entry.
• To identify potential targets for novel antiviral agents by screening a peptide library.

Main Methods:

• Screening of an overlapping E1E2 peptide library against HCV pseudoparticle infection.
• Utilizing a lentiviral reporter vector pseudotyped with E1E2 envelope proteins.
• Structure-activity relationship analysis of inhibitory peptides.

Main Results:

• A 16-residue peptide (Peptide 75) from the E2 transmembrane domain inhibited HCV pseudoparticle infection (IC50 ~0.3µM).
• Antiviral activity of Peptide 75 was sequence-specific, dependent on L-configuration and hydrophobicity.
• Peptide 75 acted post-binding and enhanced inhibition when combined with anti-CD81 antibodies.

Conclusions:

• The C-terminal region of HCV E2 protein plays a significant role in the viral entry process.
• Peptide 75 and its target interactions represent a promising avenue for developing new HCV antiviral therapies.