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

Following a rational design, a series of macrocyclic (stapled) peptidomimetics of 10Panx1, the most established peptide inhibitor of Pannexin1 (Panx1) channels, were developed and synthesized. Two macrocyclic analogues SBL-PX1-42 and SBL-PX1-44 outperformed the linear native peptide. During in vitro adenosine triphosphate (ATP) release and Yo-Pro-1 uptake assays in a Panx1-expressing tumor cell line, both compounds were revealed to be promising bidirectional inhibitors of Panx1 channel function, able to induce a two-fold inhibition, as compared to the native 10Panx1 sequence. The introduction of triazole-based cross-links within the peptide backbones increased helical content and enhanced in vitro proteolytic stability in human plasma (>30-fold longer half-lives, compared to 10Panx1). In adhesion assays, a double-stapled peptide, SBL-PX1-206 inhibited ATP release from endothelial cells, thereby efficiently reducing THP-1 monocyte adhesion to a TNF-a-activated endothelial monolayer and making it a promising candidate for future in vivo investigations in animal models of cardiovascular inflammatory disease.

Automated summary

A series of macrocyclic peptidomimetics of Pannexin1 channels were developed and synthesized, showing better performance than the linear native peptides. Two compounds, SBL-PX1-42 and SBL-PX1-44, exhibited promising bidirectional inhibitory effects on the channel function. The introduction of triazole-based cross-links in the peptides enhanced helical content and stability. One of the peptides, SBL-PX1-206, efficiently reduced monocyte adhesion to activated endothelial cells, making it a potential candidate for in vivo investigations in animal models of cardiovascular inflammatory disease.