Development of a time-resolved fluorescence resonance energy transfer assay for cyclin-dependent kinase 4 and identification of its ATP-noncompetitive inhibitors

• Published in: Analytical biochemistry Vol. 421; no. 2; pp. 368 - 377
• Main Authors: Lo, Mei-Chu, Ngo, Rachel, Dai, Kang, Li, Cong, Liang, Lingming, Lee, Josie, Emkey, Renee, Eksterowicz, John, Ventura, Manuel, Young, Stephen W., Xiao, Shou-Hua
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.02.2012
• Subjects: adenosine triphosphate; Adenosine Triphosphate - metabolism; ATP noncompetitive; CDK4; Cell Line, Tumor; Chromatography, High Pressure Liquid; cyclin-dependent kinase; Cyclin-Dependent Kinase 4 - antagonists & inhibitors; Cyclin-Dependent Kinase 4 - metabolism; drugs; energy transfer; fluorescence; Fluorescence Resonance Energy Transfer - methods; High-throughput screening; human diseases; Humans; Inhibitor; Kinase; Kinetics; Mass Spectrometry; Models, Molecular; Protein Kinase Inhibitors - pharmacology; screening; selection criteria; TR–FRET; High-throughput screening; Inhibitor; ATP noncompetitive; CDK4; Kinase; TR–FRET
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2011.10.014

Protein kinases are recognized as important drug targets due to the pivotal roles they play in human disease. Many kinase inhibitors are ATP competitive, leading to potential problems with poor selectivity and significant loss of potency in vivo due to cellular ATP concentrations being much higher than Km. Consequently, there has been growing interest in the development of ATP-noncompetitive inhibitors to overcome these problems. There are challenges to identifying ATP-noncompetitive inhibitors from compound library screens because ATP-noncompetitive inhibitors are often weaker and commonly excluded by potency-based hit selection criteria in favor of abundant and highly potent ATP-competitive inhibitors in screening libraries. Here we report the development of a time-resolved fluorescence resonance energy transfer (TR–FRET) assay for protein kinase cyclin-dependent kinase 4 (CDK4) and the identification of ATP-noncompetitive inhibitors by high-throughput screening after employing a strategy to favor this type of inhibitors. We also present kinetic characterization that is consistent with the proposed mode of inhibition.