PRFF Peptide Mimic Interferes with Toxic Fibrin-Aβ₄₂ Interaction by Emulating the Aβ Binding Interface on Fibrinogen

Area of Science:

• Neuroscience
• Biochemistry
• Vascular Biology

Background:

• Cerebrovascular dysfunction and cerebral amyloid angiopathy (CAA) are prevalent in Alzheimer's disease (AD).
• Fibrinogen's interaction with amyloid-beta 42 (Aβ42) in the brain forms plasmin-resistant clots, contributing to AD pathology.
• Current therapeutic options for AD-associated CAA are limited.

Purpose of the Study:

• To identify a therapeutic agent targeting the fibrinogen-Aβ42 interaction in Alzheimer's disease.
• To investigate a peptide's ability to inhibit clot formation and dissolve existing abnormal clots.
• To explore a novel therapeutic strategy for cerebral amyloid angiopathy.

Main Methods:

• A 13-amino acid peptide (Pα-NPGRPEPGSAGTW) was designed and synthesized.
• The peptide's interaction with Aβ42 and fibrinogen was analyzed.
• The peptide's effect on fibrin-Aβ42 complex formation and clot dissolution was evaluated.
• The peptide's specificity for inhibiting toxic interactions without affecting normal fibrin polymerization was assessed.

Main Results:

• A peptide, Pα, was identified as a potential inhibitor of the toxic fibrinogen-Aβ42 interaction.
• Pα demonstrated the ability to dissolve pre-existing plasmin-resistant abnormal clots.
• The peptide shares partial sequence similarity with a known Aβ42-binding fibrinogen fragment (PRFF).
• Pα selectively inhibits the pathological fibrin-Aβ42 interaction while preserving normal fibrin polymerization.

Conclusions:

• The identified peptide Pα shows promise as a therapeutic agent for Alzheimer's disease-associated cerebral amyloid angiopathy.
• Pα acts by competitively inhibiting the interaction between fibrinogen and Aβ42, preventing toxic clot formation.
• This peptide represents a potential new avenue for treating cerebrovascular complications in Alzheimer's disease.