Covalent Inhibitor Screening for Targeting LOXL2: Studied by Virtual Screening and Experimental Validation

Background: Lysyl oxidase-like 2 (LOXL2) is a metalloenzyme that catalyzes oxidative deamination ε-amino group of lysine. It has been found that LOXL2 is a promotor for the metastasis and invasion in kinds of tumors. Previous studies show that disulfide bonds are important components in LOXL2, and their bioactivity can be regulated by those bonds. In this way, a small molecule covalently binds to the thiol group of cysteine residue could be an effective way to change the function of LOXL2 by blocking the formation of the disulfide bond.

Objective: This investigation is aiming to screen covalent inhibitor for LOXL2.

Methods: Covalent molecule libraries of Life Chemical and Enamine were used. The structures of those molecules were optimized by using LigPrep module of Schrödinger. Then optimized by using the LigPrep module of Schrödinger to generate optimal conformations. For covalent docking, CovDock in Glide module was used for the virtual screening. Finally, wound-healing assays were performed to examine the effects of the potential inhibitors.

Results: Eight potential small molecules were selected by covalent docking from the databases (in total 7,908 candidates). ADMET evaluation indicated that all those eight small molecules satisfy the general standard. Furthermore, wound healing experiments showed that the compound (F50972176) significantly inhibits the migration of cancer cells.

Conclusion: Virtual screening and experimental verification methods were used to screen covalent inhibitors of LOXL2 by targeting functional disulfide bonds. The compound (F50972176) effectively inhibited the migration of esophageal squamous cell carcinoma cells.