Probing Thrombosis Initiation with Lasso Peptide Variants as Inhibitors to the von Willebrand Protein–Collagen Interaction

Currently, there are no peptide-based therapeutics that safely target thrombosis initiation. Anticlot medications are mostly focused on platelet interactions, leading to side effects and complications. Herein, we utilize the unique [1]rotaxane architecture of lasso peptides as a scaffold for the development of new inhibitors to the protein–protein interaction between von Willebrand factor (vWF) and collagen, which is paramount to clot initiation. The microcin J25 lasso peptide tolerates the substitution of four contiguous amino acids within its loop, leading to two variants with LWEQ and FRSH sequences grafted within the loop. Each variant shows low micromolar activity in a fluorescently linked immunosorbent assay, an in vitro test for inhibition of the collagen–vWF interaction. In addition, the lasso peptides were treated with a panel of proteases and showed exceptional stability. These peptides launch a new class of potential antithrombosis agents and also help probe the connection between peptide structure and its inhibitory, drug-like characteristics.