[The feasibility of application of reverse docking method to the selectivity studies of protein kinase inhibitors].

This investigation is to explore the feasibility of applying reverse docking method to the selectivity studies of protein kinase inhibitors. Firstly, a database that consists of 422 protein kinase structures was established through collecting the reported crystal structures or homology modeling. Then a reverse docking based method of protein kinase target screening was established, followed by the optimization of related parameters and scoring functions. Finally, seven typical selective kinase inhibitors were used to test the established method. The results show that the selective targets of these inhibitors have relatively high scoring function values (ranking in the first 35% of the tested kinase targets according to the scoring function values). This implies that the reverse docking method can be applied to the virtual screening of kinase targets and further to the selectivity studies of protein kinase inhibitors.

Pharmacophore modeling and virtual screening studies of checkpoint kinase 1 inhibitors.

In this study, chemical feature-based 3-dimensional (3D) pharmacophore models of Checkpoint kinase 1 (Chk1) inhibitors were developed based on the known inhibitors of Chk1. The best pharmacophore model Hypo1 was characterized by the best correlation coefficient (0.9577), and the lowest root mean square deviation (0.8871). Hypo1 consists of one hydrogen-bond acceptor, one hydrogen-bond donor, and two hydrophobic features, as well as one excluded volume. This pharmacophore model was further validated by both test set and cross validation methods. A comparison analysis of Hypo1 with chemical features in the active site of Chk1 indicates that the pharmacophore model Hypo1 can correctly reflect the interactions between Chk1 and its ligands. Then Hypo1 was used to screen chemical databases, including Specs and Chinese Nature Product Database (CNPD) for potential lead compounds. The hit compounds were subsequently subjected to filtering by Lipinski's rule of five and docking study to refine the retrieved hits. Finally some of the most potent (estimated) compounds were selected from the final refined hits and suggested for further experimental investigation.