Allosteric covalent inhibition of TOE1 as potential unexplored anti-cancer target: structure-based virtual screening and covalent molecular dynamics analysis

Abstract

Cancer remains a formidable challenge in therapeutic development owing to its complex molecular mechanisms and resistance to conventional treatments. Recent evidence suggests that TOE1 may play a role in cancer progression, making it an attractive target for therapeutic interventions, nevertheless, very limited research in literature has explored the potential of TOE1 inhibitors as anti-cancer. Herein, by exploring a library of 13,900 cysteine-targeted covalent inhibitors via a comprehensive virtual screening process, we sought to identify potential compounds that could be developed into effective cancer therapies against TOE1. The compounds were first screened based on their binding affinity, followed by their compliance with drug-like properties, and finally, by their effective covalent modeling to a reactive cysteine (Cys80). A total of 66 compounds, 28 compounds, and 3 compounds were found to have higher binding affinities, optimum drug-likeness, and higher covalent docking scores, respectively, than the reference compound. The top three screened compounds, 0462, 2204, and 7034, demonstrated favorable interaction profiles, covalent binding dynamics, free binding energetics, and per-residue energy contributions as compared to the reference compound. Notably, compound 0462 contributed to the highest free binding energy and significantly enhanced the stability and rigidity of TOE1, while restricting residue flexibility. This study provides an account of the molecular mechanics underpinning the covalent inhibition of TOE1, while providing a compelling case for further investigation and translation of the screened TOE1 inhibitors, particularly compound 0462, as novel therapeutics against cancer.