PMID: 28005359

Authors:

Coxon CR, Anscombe E, Harnor SJ, Martin MP, Carbain BJ, Golding BT, Hardcastle IR, Harlow LK, Korolchuk S, Matheson CJ, Newell DR, Noble ME, Sivaprakasam M, Tudhope SJ, Turner DM, Wang LZ, Wedge SR, Wong C, Griffin RJ, Endicott JA, Cano C

Title:

Cyclin-Dependent Kinase (CDK) Inhibitors; Structure-Activity Relationships and Insights into the CDK-2 Selectivity of 6-Substituted 2-Arylaminopurines.

Journal:

J Med Chem. 2016 Dec 22. doi: 10.1021/acs.jmedchem.6b01254.

Abstract:

Purines and related heterocycles substituted at C-2 with 4'-sulfamoylanilino and at C-6 with a variety of groups have been synthesized with the aim of achieving selectivity of binding to CDK2 over CDK1. 6-Substituents that favour competitive inhibition at the ATP binding site of CDK2 were identified and typically exhibited 10-80-fold greater inhibition of CDK2 compared to CDK1. Most impressive was 4-((6-([1,1'-biphenyl]-3-yl)-9H-purin-2-yl)amino) benzenesulfonamide (73) that exhibited high potency towards CDK2 (IC50 0.044 muM), but was ~ 2000-fold less active towards CDK1 (IC50 86 muM). This compound is therefore a useful tool for studies of cell cycle regulation. Crystal structures of inhibitor-kinase complexes showed that the inhibitor stabilizes a glycine-rich loop conformation that shapes the ATP ribose binding pocket, and that is preferred in CDK2, but has not been observed in CDK1. This aspect of the active site may be exploited for the design of inhibitors that distinguish between CDK1 and CDK2.