Molecular Docking and Dynamics Simulation Reveal Stable Binding of Tiliroside in the Colchicine Site of Tubulin.

BACKGROUND

The colchicine-binding site on tubulin is of particular interest for new drug development due to its role in microtubule destabilization and potential to overcome resistance to other agents. Tiliroside, a naturally occurring flavonoid glycoside, has demonstrated anticancer potential in vitro, but its interaction with tubulin has not been previously elucidated.

OBJECTIVE

This study aimed to investigate the binding of tiliroside to the tubulin site of colchicine, in comparison with colchicine.

METHODS

Molecular docking and molecular dynamics (MD) simulations were employed. Induced-fit docking predicted tiliroside binding, and redocking of colchicine was used to validate the docking protocol. MD simulations (100 ns) were conducted for both tubulin-tiliroside and tubulin-colchicine complexes.

RESULTS

Induced-fit docking predicted that tiliroside binds strongly in the colchicine site, with more favorable scoring metrics than colchicine (Glide GScore -16.77 vs -10.25, and MMGBSA ΔGbind -50.46 vs -36.62 kcal/mol). Redocking of colchicine reproduced the binding pose (root-mean-square deviation (RMSD) ~0.6 Å). MD simulations further revealed that tiliroside forms a stable complex, remaining securely bound in the pocket. Tiliroside maintained multiple hydrogen bonds and hydrophobic contacts with tubulin, similar to or more persistent than those of colchicine.

CONCLUSION

These results suggest that tiliroside can stably and snugly occupy the colchicine site of tubulin. In summary, our computational study provides structural and dynamic evidence that tiliroside is a high-affinity ligand for the colchicine site, supporting its potential as a lead compound for developing new tubulin-targeted anticancer agents.