Enhanced potency of bivalent small molecule gp41 inhibitors

Area of Science:

• Medicinal Chemistry
• Virology
• Structural Biology

Background:

• HIV-1 gp41 mediates viral entry through cell fusion.
• Developing effective fusion inhibitors is crucial for HIV-1 therapy.
• Peptidomimetics offer a promising scaffold for drug design.

Purpose of the Study:

• To design and synthesize novel peptidomimetic inhibitors targeting HIV-1 gp41.
• To enhance the fusion inhibitory activity of existing inhibitors.
• To investigate structure-activity relationships for improved potency.

Main Methods:

• Modification of peptidomimetics to increase interaction with gp41 HR1.
• Synthesis of monomeric and dimeric inhibitor structures.
• Biophysical characterization using fluorescence and Surface Plasmon Resonance (SPR).
• Assessment of HIV-1 gp41-mediated cell fusion inhibition.

Main Results:

• Dimeric inhibitors showed 40-60 times greater potency than monomers.
• Inhibitor potency correlated better with slow off-rates than binding affinity.
• SPR data supported a bidentate interaction model for dimers with the HR1 trimer.
• High cooperativity in fusion inhibition suggested enhanced potency.

Conclusions:

• Symmetrical dimeric peptidomimetics are highly effective HIV-1 fusion inhibitors.
• Targeting multiple hydrophobic pockets on gp41 HR1 enhances inhibitor potency.
• Further optimization of dimeric or higher-order structures could yield potent non-peptide inhibitors.