Evaluation of LDV-Related Peptides as Cell-Adhesive Molecules Targeting α4β1 Integrin

Integrin α4β1 plays a central role in immune cell adhesion and trafficking and contributes to the adhesion of mesenchymal cells, making it a valuable target for designing cell-adhesive biomaterials. Peptide ligands based on the Leu-Asp-Val (LDV) motif of fibronectin have been widely studied, yet their minimal active sequences and potential as cell-adhesive molecules remain insufficiently characterized. Here, we systematically evaluated a panel of LDV-related peptides for their ability to promote α4β1-mediated adhesion of Jurkat T cells. Among six candidates, EILDVPST, derived from the CS1 domain of fibronectin, exhibited the strongest adhesion activity. Truncation and alanine-scanning analyses identified EILDVPS as the minimal sequence with full activity, with Leu and Asp serving as the critical binding core and surrounding residues providing structural support. The cyclization of EILDVPS markedly enhanced its adhesion-promoting activity, providing direct evidence that conformational constraint increases α4β1-binding affinity. Comparative assays with the high-affinity peptidomimetic ligands BIO1211-C and LLP2A-C demonstrated that although cEILDVPS was less potent, it supported long-term adhesion culture of T cells, comparable to that achieved with these ligands. Together, these findings establish EILDVPS as a minimal α4β1-binding motif, demonstrate the utility of cyclization for enhancing activity, and highlight the potential of LDV-based peptides for the adhesion culture of α4β1-expressing cells and development of integrin-targeted biomaterials.