Peacor Brendan C, Ramsay Christopher M, Waters Marcey L
Department of Chemistry , University of North Carolina at Chapel Hill , CB 3290 , Chapel Hill , NC 27599 , USA . Email:
Chem Sci. 2017 Feb 1;8(2):1422-1428. doi: 10.1039/c6sc03003c. Epub 2016 Oct 20.
Post-translational modifications (PTMs) on histone tails act in diverse combinations in the 'histone code' to control gene expression, with dysregulation observed in a variety of diseases. However, detection and sensing methods are limited, expensive, and/or low-throughput, including MS and antibody based detection. We found that by combining four synthetic receptors developed by dynamic combinatorial chemistry (DCC) in an indicator displacement system, we are able to create a pattern-based sensor platform that can discriminate single PTMs such as methylation and acetylation on a representative histone peptide with 100% accuracy as well as peptides bearing both dimethyl and trimethyl lysine in the presence of arginine methylation, which has not previously been demonstrated, and can even correctly distinguish the position of lysine methylation individually or in the presence of other PTMs. To extend this approach, a full panel of thirteen analytes containing different combinations of PTMs were classified with 96 ± 1% overall accuracy in a 50% left-out analysis, demonstrating the robustness and versatility of the sensor array. Finally, the sensor platform was also used to demonstrate proof of concept for enzymatic assays by analysing the mock reaction of a threonine kinase, successfully identifying analytes representative of substrate conversion both with and without neighboring PTMs. This work provides a rapid platform for the analysis of peptides bearing complex modifications and highlights the utility of receptors discovered though DCC that display variations in binding affinity and selectivity.
组蛋白尾部的翻译后修饰（PTMs）以“组蛋白密码”中的多种组合方式发挥作用，以控制基因表达，在多种疾病中都观察到了这种调控异常。然而，检测和传感方法有限、昂贵且/或通量低，包括基于质谱和抗体的检测方法。我们发现，通过在指示剂置换系统中组合动态组合化学（DCC）开发的四种合成受体，我们能够创建一个基于模式的传感器平台，该平台可以以100%的准确率区分代表性组蛋白肽上的单个PTMs，如甲基化和乙酰化，以及在存在精氨酸甲基化的情况下同时带有二甲基和三甲基赖氨酸的肽，这在以前尚未得到证实，甚至可以单独或在存在其他PTMs的情况下正确区分赖氨酸甲基化的位置。为了扩展这种方法，在50%留一法分析中，一组包含不同PTM组合的13种分析物以96±1%的总体准确率进行了分类，证明了传感器阵列的稳健性和通用性。最后，该传感器平台还通过分析苏氨酸激酶的模拟反应来证明酶促测定的概念验证，成功识别了有和没有相邻PTM的底物转化代表性分析物。这项工作为分析带有复杂修饰的肽提供了一个快速平台，并突出了通过DCC发现的具有不同结合亲和力和选择性的受体的实用性。
