Revealing DNA's Secret Structures with Ruthenium: From the Test Tube, to the Cell

除了沃森-克里克的双螺旋结构，DNA还有更多的东西。作为一种柔性聚合物，它以不同的方式折叠，采用许多不同的二级结构。(I)人们对这些结构知之甚少--它们是如何以及何时形成的，它们的作用是什么，它们的结构与它们的作用是如何联系的。即便如此，这种“替代”结构与基因的开关有关，因此也与糖尿病和癌症等遗传性疾病有关。这个3.5年的博士生课程由EPSRC博士培训伙伴关系资助，重点研究这样的结构之一，I-Motif(Im)。2018年证实了Im在生物体中的存在，(Ii)但对其生物结构/功能关系知之甚少，由于缺乏可应用于活细胞和生物体的有效检测方法，研究受到阻碍。然而，我们最近发现了一种Ru络合物，它可以在体外通过磷光寿命延长在其他DNA形式存在的情况下检测Im，(Iii)并且可能与生命系统兼容。这个项目的目标是改进我们的先导化合物，增加其反应的强度和特异性，提高我们对其磷光开关的理解，并开始将这项研究从试管转化为细胞的工作。因此，由约翰·菲尔登博士领导的这个项目是高度跨学科的。它将涉及广泛的技术培训，从合成新的配体和络合物，到表征它们与DNA的相互作用及其对细胞的影响，并涉及内部和外部合作。

iThere is a lot more to DNA than the Watson-Crick double helix. As a flexible polymer, it folds in different ways adopting many different secondary structures.(i) Much less is known about these structures - how and when they form, what they do and how their structure relates to their role. Even so, such "alternative" structures have been linked to switch on/off of genes, and thus genetic diseases such as diabetes and cancer.This 3.5 year PhD studentship is funded by an EPSRC Doctoral Training Partnership and focuses on one such structure, the i-Motif (iM). Existence of iM in organisms was proven in 2018,(ii) but little is known about its biological structure/function relationships, and research is held back by a lack of effective detection methods that can be applied to live cells and organisms. However, we recently discovered a ruthenium complex that can, in vitro, detect iM in the presence of other DNA forms through a phosphorescence lifetime increase,(iii) and is likely compatible with living systems. The goal of this studentship is to improve our lead compound, increasing the strength and specificity of its response, improve our understanding of its phosphorescence switch on, and begin the work of translating this research from the test tube to cells. As such, the project, led by Dr John Fielden, is highly interdisciplinary. It will involve training in a wide range of techniques, from synthesis of new ligands and complexes, to characterisation of their interaction with DNA and their effect in cells, and involves both internal and external collaborations.