Design, Synthesis and Evaluation of 2,5-Diketopiperazines as Inhibitors of the MDM2-p53 Interaction
作者:Mariell Pettersson、Maria Quant、Jaeki Min、Luigi Iconaru、Richard W. Kriwacki、M. Brett Waddell、R. Kiplin Guy、Kristina Luthman、Morten Grøtli
DOI:10.1371/journal.pone.0137867
日期:——
The transcription factor p53 is the main tumour suppressor in cells and many cancer types have p53 mutations resulting in a loss of its function. In tumours that retain wild-type p53 function, p53 activity is down-regulated by MDM2 (human murine double minute 2) via a direct protein—protein interaction. We have designed and synthesised two series of 2,5-diketopiperazines as inhibitors of the MDM2-p53 interaction. The first set was designed to directly mimic the α-helical region of the p53 peptide, containing key residues in the i, i+4 and i+7 positions of a natural α-helix. Conformational analysis indicated that 1,3,6-trisubstituted 2,5-diketopiperazines were able to place substituents in the same spatial orientation as an α-helix template. The key step of the synthesis involved the cyclisation of substituted dipeptides. The other set of tetrasubstituted 2,5-diketopiperazines were designed based on structure-based docking studies and the Ugi multicomponent reaction was used for the synthesis. This latter set comprised the most potent inhibitors which displayed micromolar IC50-values in a biochemical fluorescence polarisation assay.
转录因子p53是细胞中的主要肿瘤抑制因子,许多癌症类型中存在p53突变,导致其功能丧失。在保持野生型p53功能的肿瘤中,p53的活性通过MDM2(人类小鼠双分钟2)通过直接的蛋白-蛋白相互作用被下调。我们设计并合成了两系列2,5-二酮哌嗪,作为MDM2-p53相互作用的抑制剂。第一组是直接模拟p53肽的α-螺旋区域,包含天然α螺旋中i、i+4和i+7位置的关键氨基酸残基。构象分析表明,1,3,6-三取代的2,5-二酮哌嗪能够以与α-螺旋模板相同的空间取向放置取代基。合成的关键步骤是取代二肽的环化。另一组四取代的2,5-二酮哌嗪是基于结构基础的对接研究设计的,并采用Ugi多组分反应进行合成。这后一组包含了最有效的抑制剂,在生化荧光偏振测定中显示出微摩尔IC50值。