Developing an artificial intelligence-generated peptide targeting platelet-type von Willebrand disease.

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Platelet-type von Willebrand disease (PT-VWD) is a rare bleeding disorder caused by gain-of-function mutations in platelet glycoprotein Ibα (GPIbα).
• These mutations result in hyperactive protein-protein interactions (PPIs) between GPIbα and von Willebrand factor (VWF), leading to pathological platelet aggregation.
• Currently, no targeted therapies exist for PT-VWD, despite its well-defined genetic basis.

Purpose of the Study:

• To develop a peptide inhibitor that selectively targets the aberrant GPIbα-VWF interaction in PT-VWD.
• To validate the efficacy and specificity of designed peptide inhibitors using in vitro and ex vivo assays.
• To explore the potential of identified inhibitors as diagnostic tools for PT-VWD.

Main Methods:

• Utilized the In Silico Protein Synthesizer to design and screen 10,000 peptides for affinity and specificity against mutated GPIbα (GPIbαMet239Val).
• Conducted functional validation using in vitro assays with GPIbαGly233Val and Met239Val variants, alongside ex vivo platelet assays from PT-VWD patients.
• Employed structural modeling to predict the binding site and mechanism of action of the lead peptide inhibitor.

Main Results:

• Identified a peptide inhibitor, G14, demonstrating potent and selective inhibition of the GPIbαGly233Val, Met239Val-VWF PPI.
• G14 exhibited picomolar affinity (6.6 pM) for the mutated GPIbα and selectively disrupted the VWF interaction without affecting wild-type GPIbα or VWF alone.
• Ex vivo assays showed G14 inhibited VWF binding and ristocetin-induced platelet agglutination in PT-VWD patient samples, with no effect on healthy controls.

Conclusions:

• The G14 peptide represents a highly specific inhibitor of the disease-associated GPIbα-VWF interaction, providing proof-of-concept for targeted PT-VWD therapeutics.
• The specificity of G14 suggests its potential utility as a diagnostic tool for identifying PT-VWD.
• The study highlights the effectiveness of artificial intelligence in designing precision therapeutics for disease-specific PPIs.