Iman A. Mansi*, Mahmoud A. Al-Sha`er*, Nizar M. Mhaidat, Mutasem O. Taha and Rand Shahin
Background: 3-Phosphoinositide Dependent Protein Kinase-1 (PDK1) is being lately considered as an attractive and forthcoming anticancer target. A Protein Data Bank (PDB) co-crystallized crystal provides not only rigid theoretical data but also a realistic molecular recognition data that can be explored and used to discover new hits.
Objective: This incited us to investigate the co crystallized ligands' contacts inside the PDK1 binding pocket via a structure-based receptor-ligand pharmacophore generation technique in Discovery Studio 4.5 (DS 4.5).
Method: Accordingly, 35 crystals for PDK1 were collected and studied. Every single receptor-ligand interaction was validated and the significant ones were converted into their corresponding pharmacophoric features. The generated pharmacophores were scored by the Receiver Operating Characteristic (ROC) curve analysis.
Results: Consequently, 169 pharmacophores were generated and sorted, 11 pharmacophores acquired a good ROC-AUC results of 0.8 and a selectivity value above 8. Pharmacophore 1UU3_2_01 was used in particular as a searching filter to screen NCI database because of its acceptable validity criteria and its distinctive positive ionizable feature. Several low micromolar PDK1 inhibitors were revealed. The most potent hit illustrated anti-PDK1 IC50 values of 200 nM with 70% inhibition against SW480 cell lines.
Conclusion: Eventually, the active hits were docked inside the PDK1 binding pocket and the recognition points between the active hits and the receptor were analyzed that led to the discovery of new scaffolds as potential PDK1 inhibitors.
PDK1; Cancer; Co-crystallized structure; Docking; Pharmacophore; Roc analysis; Discovery studio molecular design
Faculty of Pharmaceutical Sciences, The Hashemite University, P.O. Box 330127 Zarqa, 13133, Faculty of Pharmacy, Zarqa University, Zarqa, 13132, Clinical Pharmacy Department, Faculty of Pharmacy, Jordan University of Science & Technology, Drug Design Center, Faculty of Pharmacy, University of Jordan, Faculty of Pharmaceutical Sciences, The Hashemite University, P.O. Box 330127 Zarqa, 13133