In Silico Prediction of Tetrastatin-Derived Peptide Interactions with αvβ3 and α5β1 Integrins

Background/Objectives: Tetrastatin, the globular non collagenous (NC1) domain of the α4 chain of collagen IV, was previously demonstrated to inhibit melanoma progression. We identified the minimal active sequence (QKISRCQVCVKYS: QS-13) that reproduced the anti-tumor effects of whole Tetrastatin and demonstrated its anti-angiogenic activity mediated through αvβ3 and α5β1 binding. As QS-13 peptide was not fully soluble in aqueous solution, we designed new peptides with better water solubility. The present work aimed to investigate the interactions of ten QS-13-derived peptides, exhibiting improved hydro-solubility, with αvβ3 and α5β1 integrins. Methods: Using bioinformatics tools such as GROMACS, VMD, and the Autodock4 suite, we investigated the ability of the substituted peptides to bind αvβ3 and α5β1 integrins in silico. Results: We demonstrated in silico that all substituted peptides were able to bind both integrins at the RGD-binding site and determined their theoretical binding energy. Conclusions: The new soluble peptides should be able to compete with natural integrin ligands such as fibronectin, but also FGF1, FGF2, IGF1, and IGF2. Taken together, these findings suggest that the QS-13-derived peptides are reliable anti-angiogenic and anti-tumor agents.