Conformations and pharmacophores of cyclic RGD containing peptides which selectively bind integrin alpha(v)beta3

Area of Science:

• Medicinal Chemistry
• Biochemistry
• Structural Biology

Background:

• Integrin alpha(v)beta3 and alphaIIb3 receptors are key targets in various diseases.
• Cyclic peptides offer constrained structures for high-affinity ligand design.
• The RGDDV and RGDY(Me)R pharmacophores are known to interact with integrins.

Purpose of the Study:

• To characterize the solution conformations of cyclic peptides containing RGDDV and RGDY(Me)R pharmacophores.
• To investigate the structure-activity relationships of these pharmacophores in cyclic peptides.
• To provide insights for designing novel peptidomimetics targeting integrins.

Main Methods:

• 1H-NMR spectroscopy in H2O and DMSO-d6 for conformational analysis.
• Molecular modeling simulations to predict and analyze peptide structures.
• Structure-activity relationship (SAR) studies focusing on ligand-receptor interactions.

Main Results:

• Detailed conformational characterization of cyclic peptides in different solution environments.
• Identification of low to sub-nanomolar inhibition of integrin alpha(v)beta3 by both pharmacophores.
• Potent binding of RGDY(Me)R containing peptides to integrin alphaIIb3 was observed.
• Correlation between specific orientations of chemical features and biological activity.

Conclusions:

• Solution conformations of RGDDV and RGDY(Me)R cyclic peptides are crucial for their potent integrin inhibitory activity.
• These findings are valuable for the rational design of peptidomimetics.
• Understanding the SAR of these pharmacophores can lead to improved therapeutic agents.