Chen Peiling, Chaikuad Apirat, Bamborough Paul, Bantscheff Marcus, Bountra Chas, Chung Chun-Wa, Fedorov Oleg, Grandi Paola, Jung David, Lesniak Robert, Lindon Matthew, Müller Susanne, Philpott Martin, Prinjha Rab, Rogers Catherine, Selenski Carolyn, Tallant Cynthia, Werner Thilo, Willson Timothy M, Knapp Stefan, Drewry David H
Department of Chemical Biology, GlaxoSmithKline , Research Triangle Park, 5 Moore Drive, Research Triangle Park, North Carolina 27709-3398, United States.
Nuffield Department of Clinical Medicine, Structural Genomics Consortium, University of Oxford , Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, United Kingdom.
J Med Chem. 2016 Feb 25;59(4):1410-24. doi: 10.1021/acs.jmedchem.5b00209. Epub 2015 Apr 6.
Bromodomains are acetyl-lysine specific protein interaction domains that have recently emerged as a new target class for the development of inhibitors that modulate gene transcription. The two closely related bromodomain containing proteins BAZ2A and BAZ2B constitute the central scaffolding protein of the nucleolar remodeling complex (NoRC) that regulates the expression of noncoding RNAs. However, BAZ2 bromodomains have low predicted druggability and so far no selective inhibitors have been published. Here we report the development of GSK2801, a potent, selective and cell active acetyl-lysine competitive inhibitor of BAZ2A and BAZ2B bromodomains as well as the inactive control compound GSK8573. GSK2801 binds to BAZ2 bromodomains with dissociation constants (KD) of 136 and 257 nM for BAZ2B and BAZ2A, respectively. Crystal structures demonstrated a canonical acetyl-lysine competitive binding mode. Cellular activity was demonstrated using fluorescent recovery after photobleaching (FRAP) monitoring displacement of GFP-BAZ2A from acetylated chromatin. A pharmacokinetic study in mice showed that GSK2801 had reasonable in vivo exposure after oral dosing, with modest clearance and reasonable plasma stability. Thus, GSK2801 represents a versatile tool compound for cellular and in vivo studies to understand the role of BAZ2 bromodomains in chromatin biology.
溴结构域是乙酰赖氨酸特异性蛋白质相互作用结构域，最近已成为开发调节基因转录抑制剂的新靶点类别。两种密切相关的含溴结构域蛋白BAZ2A和BAZ2B构成了调节非编码RNA表达的核仁重塑复合体（NoRC）的核心支架蛋白。然而，BAZ2溴结构域的可成药潜力较低，迄今为止尚未发表过选择性抑制剂。在此，我们报告了GSK2801的研发情况，它是一种强效、选择性且具有细胞活性的BAZ2A和BAZ2B溴结构域的乙酰赖氨酸竞争性抑制剂，以及无活性对照化合物GSK8573。GSK2801与BAZ2溴结构域结合，对BAZ2B和BAZ2A的解离常数（KD）分别为136和257 nM。晶体结构显示出典型的乙酰赖氨酸竞争性结合模式。通过光漂白后荧光恢复（FRAP）监测GFP-BAZ2A从乙酰化染色质上的位移，证明了其细胞活性。在小鼠体内进行的药代动力学研究表明，GSK2801口服给药后在体内具有合理的暴露量，清除率适中且血浆稳定性良好。因此，GSK2801是一种多功能工具化合物，可用于细胞和体内研究，以了解BAZ2溴结构域在染色质生物学中的作用。
