Development of novel photochemical probes to investigate quadruplex DNA interactome in livings cells

基因组DNA主要折叠成双链结构。然而，富含鸟嘌呤的区域可以折叠成称为G-四链体（G4）的替代DNA结构，这是最近在人类细胞中观察到的。G4与基因组的不稳定性、基因表达和复制的调节有关，并且它们是一系列疾病的潜在药物靶点。虽然在过去的十年中，G4 DNA结构的表征取得了重大进展，但仍然缺乏对细胞中负责G4重组的蛋白质的理解，这是进一步阐明G4生物学意义的关键。该项目旨在通过开发可以标记活细胞中与G4结合的蛋白质的光活化探针来弥合这一差距。我们最近证明，已知与G4结合的Pt（II）络合物也可以在可见光照射下有效地产生短寿命的活性氧（ROS）。我们建议，这些活性氧可以催化苯酚-生物素试剂和蛋白质之间的已知反应，这将选择性地生物素化只有蛋白质本地的G4，提供了一个富集处理定量蛋白质组学方法的分析。

Genomic DNA is mainly folded into a double-stranded structure. However, guanine-rich regions can fold into alternative DNA structures called G-quadruplexes (G4), which have been recently visualized in human cells. G4s have been associated with genomic instability, regulation of gene expression and replication, and they are potential drug targets in a range of diseases. While the past decade has seen significant advances in the characterisation of G4 DNA structures, there remains a significant lack of understanding of the proteins responsible for G4-recongition in cells, which is key to further elucidate G4s' biological significance. This project aims to bridge this gap by developing photoactivatable probes that can label proteins bound to G4s in living cells. We recently demonstrated that Pt(II) complexes known to bind to G4s can also efficiently generate short-lived reactive oxygen species (ROS) under visible-light irradiation. We propose that these ROS can catalyse a known reaction between phenol-biotin reagents and proteins which will selectively biotinylate only proteins local to the G4, providing an enrichment handle for analysis by quantitative proteomics methods.