Cox Oakley B, Krojer Tobias, Collins Patrick, Monteiro Octovia, Talon Romain, Bradley Anthony, Fedorov Oleg, Amin Jahangir, Marsden Brian D, Spencer John, von Delft Frank, Brennan Paul E
Structural Genomics Consortium (SGC) , University of Oxford , Oxford OX3 7DQ , UK.
Target Discovery Institute (TDI) , Nuffield Department of Medicine , University of Oxford , Oxford OX3 7FZ , UK . Email:
Chem Sci. 2016 Mar 1;7(3):2322-2330. doi: 10.1039/c5sc03115j. Epub 2015 Dec 22.
Research into the chemical biology of bromodomains has been driven by the development of acetyl-lysine mimetics. The ligands are typically anchored by binding to a highly conserved asparagine residue. Atypical bromodomains, for which the asparagine is mutated, have thus far proven elusive targets, including PHIP(2) whose parent protein, PHIP, has been linked to disease progression in diabetes and cancers. The PHIP(2) binding site contains a threonine in place of asparagine, and solution screening have yielded no convincing hits. We have overcome this hurdle by combining the sensitivity of X-ray crystallography, used as the primary fragment screen, with a strategy for rapid follow-up synthesis using a chemically-poised fragment library, which allows hits to be readily modified by parallel chemistry both peripherally and in the core. Our approach yielded the first reported hit compounds of PHIP(2) with measurable IC values by an AlphaScreen competition assay. The follow-up libraries of four poised fragment hits improved potency into the sub-mM range while showing good ligand efficiency and detailed structural data.
对溴结构域化学生物学的研究是由乙酰赖氨酸模拟物的发展推动的。这些配体通常通过与一个高度保守的天冬酰胺残基结合而锚定。对于天冬酰胺发生突变的非典型溴结构域，迄今为止已证明是难以捉摸的靶点，包括PHIP(2)，其母体蛋白PHIP与糖尿病和癌症的疾病进展有关。PHIP(2)结合位点含有一个苏氨酸而非天冬酰胺，溶液筛选未产生令人信服的结果。我们通过将用作主要片段筛选的X射线晶体学的灵敏度与使用化学平衡片段库进行快速后续合成的策略相结合，克服了这一障碍，该策略允许通过平行化学在外围和核心部位对命中物进行轻松修饰。我们的方法通过AlphaScreen竞争测定法产生了首批报道的具有可测量IC值的PHIP(2)命中化合物。四个平衡片段命中物的后续库将效力提高到亚毫摩尔范围，同时显示出良好的配体效率和详细的结构数据。
