Structure-Based Design and Synthesis of Stapled ¹⁰Panx1 Analogues for Use in Cardiovascular Inflammatory Diseases

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Pannexin1 (Panx1) channels play a role in cellular processes and disease.
• The native peptide ¹⁰Panx1 is an established inhibitor of Panx1 channels.
• Developing more stable and potent peptide inhibitors is crucial for therapeutic applications.

Purpose of the Study:

• To design and synthesize macrocyclic peptidomimetics of ¹⁰Panx1.
• To evaluate the inhibitory activity and stability of these novel compounds against Panx1 channels.
• To assess the potential of these peptidomimetics in reducing inflammation in cellular models.

Main Methods:

• Rational design and synthesis of macrocyclic (
• In vitro assays including adenosine triphosphate (ATP) release and Yo-Pro-1 uptake in Panx1-expressing tumor cell lines.
• Proteolytic stability assays in human plasma and adhesion assays using endothelial cells.

Main Results:

• Two macrocyclic analogues, SBL-PX1-42 and SBL-PX1-44, demonstrated superior inhibition of Panx1 channel function compared to the native ¹⁰Panx1 peptide.
• Triazole-based cross-links enhanced helical content and significantly improved in vitro proteolytic stability (>30-fold longer half-lives).
• A "double-stapled" peptide, SBL-PX1-206, effectively reduced ATP release from endothelial cells and inhibited monocyte adhesion to activated endothelial cells.

Conclusions:

• Macrocyclic peptidomimetics of ¹⁰Panx1 exhibit enhanced potency and stability.
• These compounds are promising bidirectional inhibitors of Panx1 channel function.
• SBL-PX1-206 shows potential for treating cardiovascular inflammatory diseases and warrants further in vivo investigation.