A combination of molecular docking, receptor-guided QSAR, and molecular dynamics simulation studies of S-trityl-l-cysteine analogues as kinesin Eg5 inhibitors

Kinesin Eg5 plays an essential role in the early stages of mitosis, and it is an interesting drug target for the design of potent inhibitors. In this work, combined molecular modeling studies of molecular docking, receptor-guided QSAR methodology, and molecular dynamics (MD) simulation were performed on a series of novel S-trityl-l-cysteine (STLC) analogues as Eg5 inhibitors to understand the structural features and key residues which are involved in the inhibition. Molecular docking study was used to find the actual conformations of STLC analogues in the binding site of Eg5. Multiple linear regression (MLR), artificial neural network (ANN), and support vector machine (SVM) models were developed by the conformation which was obtained by performing docking studies. The satisfactory result of the SVM model (R2 = 0.962, SE = 0.210, RMSE = 0.190, and Q2LOO = 0.930) demonstrated the superiority of this model over other models. Also, the satisfactory agreement between experiment and predicted inhibitory values suggested that the SVM model represents good correlation and predictive power. Molecular docking was used to study the functionalities of active molecular interaction between inhibitors and Eg5. Moreover, molecular dynamics (MD) simulation was performed on the best inhibitor-Eg5 complex to investigate the stability of docked conformation and to study the binding interactions in detail. The MD simulation result showed four hydrogen bond interactions with Eg5 residues including Gly117, Glu116, Gly117, and Glu118. The outcome of this study can be used as a guideline to better interpret the protein-ligand interaction and also can assist in the designing and development of more potent Eg5 inhibitors.