Moebitz, Henrik, Jacob, Sandra and Drueckes, Peter (2015) Type II inhibitors targeting CDK2. acs chemical biology, 10 (9). pp. 2116-2125. ISSN 1554-89291554-8937

Abstract

Kinases can switch between active and inactive conformations of the ATP/Mg2+ binding motif DFG motif which has been explored by the development of type I or type II inhibitors. However, factors modulating DFG conformational remain poorly understood. We chose CDK2 as a model system to study the DFG out transition on a target that was thought to have an inaccessible DFG-out conformation using site directed mutagenesis of key residues identified in structural comparisons in conjunction with biochemical and biophysical characterization of the generated mutants. We identified key residues that facilitate the DFG out movement facilitating binding of type II inhibitors. However, surprisingly we also found that wild type CDK2 is able to bind type II inhibitors. Using protein crystallography structural analysis of the CDK2 complex with a aminopyrimidine-phenyl urea inhibitor (K03861) revealed a canonical type II binding mode and the first available type II CDK2 co-crystal structure. We found that the identified type II inhibitors compete with binding of activating cyclins. In addition, analysis of the binding kinetics of the identified inhibitors revealed slow dissociation off-rates. The study highlights the importance of residues that may be distant to the ATP binding pocket in modulating the energetics of the DFG out transition and hence inhibitor binding. The presented data provide also the foundation for a new class of slow off-rate cyclin competitive CDK2 inhibitors targeting the inactive DFG-out state of this important kinase target.

Item Type:	Article
Date Deposited:	26 Apr 2016 23:45
Last Modified:	26 Apr 2016 23:45
URI:	https://oak.novartis.com/id/eprint/25739