Structure-Based Design of Potent Selective Nanomolar Type-II Inhibitors of Glycogen Synthase Kinase-3β
Matthew Davies, Rocío Benítez‐Fernández, Concepción Pérez, Sven Jakupovic, Philip J. Welsby, Klaudia Rzepecka, Jane Alder, Colin Davidson, Ana Martı́nez, Joseph M. Hayes
Abstract
For the first time, the in silico design, screening, and in vitro validation of potent GSK-3β type-II inhibitors are presented. In the absence of crystallographic evidence for a DFG-out GSK-3β activation loop conformation, computational models were designed using an adapted DOLPHIN approach and a method consisting of Prime loop refinement, induced-fit docking, and molecular dynamics. Virtual screening of the Biogenics subset from the ZINC database led to an initial selection of 20 Phase I compounds revealing two low micromolar inhibitors in an isolated enzyme assay. Twenty more analogues (Phase II compounds) related to the hit [pyrimidin-2-yl]amino–furo[3,2-b]furyl–urea scaffold were selected for structure–activity relationship analysis. The Phase II studies led to five highly potent nanomolar inhibitors, with compound 23 (IC50 =0.087 μM) > 100 times more potent than the best Phase I inhibitor, and selectivity for GSK-3β inhibition compared to homologous kinases was observed. Ex vivo experiments (SH-SY5Y cell lines) for tau hyperphosphorylation revealed promising neuroprotective effects at low micromolar concentrations. The type-II inhibitor design has been unraveled as a potential route toward more clinically effective GSK-3β inhibitors.