Moreno-Yruela Carlos, Olsen Christian A
Center for Biopharmaceuticals and Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark.
ACS Med Chem Lett. 2022 Mar 16;13(5):779-785. doi: 10.1021/acsmedchemlett.1c00702. eCollection 2022 May 12.
Histone deacetylases (HDACs) 1-3 regulate chromatin structure and gene expression. These three enzymes are targets for cancer chemotherapy and have been studied for the treatment of immune disorders and neurodegeneration, but there is a lack of selective pharmacological tool compounds to unravel their individual roles. Potent inhibitors of HDACs 1-3 often display slow-binding kinetics, which causes a delay in inhibitor-enzyme equilibration and may affect assay readout. Here we compare the potencies and selectivities of slow-binding inhibitors measured by discontinuous and continuous assays. We find that entinostat, a clinical candidate, inhibits HDACs 1-3 by a two-step slow-binding mechanism with lower potencies than previously reported. In addition, we show that RGFP966, commercialized as an HDAC3-selective probe, is a slow-binding inhibitor with inhibitor constants of 57, 31, and 13 nM against HDACs 1-3, respectively. These data highlight the need for thorough kinetic investigation in the development of selective HDAC probes.
组蛋白去乙酰化酶（HDACs）1 - 3调节染色质结构和基因表达。这三种酶是癌症化疗的靶点，并且已针对免疫紊乱和神经退行性疾病的治疗进行了研究，但缺乏选择性药理学工具化合物来阐明它们各自的作用。HDACs 1 - 3的强效抑制剂通常表现出慢结合动力学，这会导致抑制剂与酶达到平衡的延迟，并可能影响检测读数。在此，我们比较了通过间断和连续检测测定的慢结合抑制剂的效力和选择性。我们发现，临床候选药物恩替诺特通过两步慢结合机制抑制HDACs 1 - 3，其效力低于先前报道。此外，我们表明，作为HDAC3选择性探针商业化的RGFP966是一种慢结合抑制剂，其对HDACs 1 - 3的抑制常数分别为57、31和13 nM。这些数据突出了在开发选择性HDAC探针时进行全面动力学研究的必要性。
