Mechanism-Based Rational Discovery and In Vitro Evaluation of Novel Microtubule Stabilizing Agents with Non-Taxol-Competitive Activity

Zuniga-Bustos, Matias; Vasquez, Pilar A.; Jana, Gonzalo A.; Guzman, Jose L.; Alderete, Joel B.; Jimenez, Veronica A.

Abstract

Microtubules (MT) are cytoskeletal polymers of alpha beta-tubulin dimers that play a critical role in many cellular functions. Diverse antimitotic drugs bind to MT and disrupt their dynamics acting as MT stabilizing or destabilizing agents. The occurrence of undesired side effects and drug resistance encourages the search for novel MT binding agents with chemically diverse structures and different interaction profiles compared to known active compounds. This work reports the rational discovery of seven novel MT stabilizers using a combination of molecular modeling methods and in vitro experimental assays. Virtual screening, similarity filtering, and molecular mechanics generalized Born surface area (MM/GBSA) binding free energy refinement were employed to select seven potential candidates with high predicted affinity toward the non-taxoid site for MT stabilizers on beta-tubulin. MD simulations of 150 ns on reduced MT models suggest that candidate compounds strengthen the longitudinal interactions between tubulin dimers across protofilaments, which is a primary molecular mechanism of action for known MT stabilizers. In vitro MT polymerization assays confirmed that all candidates promote MT assembly at concentrations of >50 mM and exhibit noncompetitive MT polymerization profiles when cotreating with Taxol. Preliminary HeLa cell viability assays revealed a moderate cytotoxic effect for the compounds under study at 100 mu M concentration. These results support the validity of our rational discovery strategy and the use of molecular modeling methods to pursue the search and optimization of new MT targeting agents.

Más información

Título según WOS: ID WOS:000543717300049 Not found in local WOS DB
Título de la Revista: JOURNAL OF CHEMICAL INFORMATION AND MODELING
Volumen: 60
Número: 6
Editorial: AMER CHEMICAL SOC
Fecha de publicación: 2020
Página de inicio: 3204
Página final: 3213
DOI:

10.1021/acs.jcim.9b01133

Notas: ISI