Tissue factor derived β-hairpin peptides that bind and inhibit FVII activity

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• The Tissue Factor (TF):Factor VII (FVII) complex initiates blood coagulation, making it a key therapeutic target.
• Inhibiting TF:FVII interaction can prevent coagulation cascade amplification.
• Targeting this complex offers a specific and timely approach to regulate coagulation.

Purpose of the Study:

• To design small cyclic peptides that mimic the TF region interacting with FVII.
• To create TF-mimics capable of inhibiting the TF:FVII protein-protein interaction.
• To validate the FVII residues 365-369 as a target site for coagulation inhibitors.

Main Methods:

• Design of four cyclic peptides incorporating TF β-strands (106-110 and 123-128) and proline-proline dipeptides.
• Disulfide bond formation for structural stabilization and protease resistance.
• Structural characterization using Circular Dichroism (CD), Nuclear Magnetic Resonance (NMR), and molecular simulations.
• Functional assessment via Factor X-generating chromogenic assays.

Main Results:

• Two cyclic peptides (D-Pro-L-Pro and D-Pro-D-Pro moieties) adopted stable β-hairpin conformations.
• These active peptides successfully recapitulated TF structure and bound FVII.
• The active peptides inhibited FVII activity in a Factor X-generating assay.
• Two other designed peptides were disordered and inactive.

Conclusions:

• The study validates the design of cyclic peptides as TF-mimics.
• The findings confirm FVII residues 365-369 as a viable target site for developing novel coagulation inhibitors.
• This approach offers a promising strategy for therapeutic regulation of the coagulation cascade.