Copper-modified G-Quadruplex DNA as EPR Probes for Precise Distance Measurements

铜修饰的 G-四链体 DNA 作为 EPR 探针进行精确距离测量

• 批准号: 499176469
• 负责人: Professor Dr. Guido Clever
• 金额: --
• 依托单位: Forschungsgebiet Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/499176469?language=en
• 关键词: Copper; modified; Quadruplex; DNA; EPR

DNA G-quadruplexes show a pronounced tendency to form higher-order structures, such as π-stacked dimers, beads-on-a-string wires, and aggregates with aromatic binding partners, relevant in medicinal targeting of telomers and oncogenes. Reliable methods for determining the structure of these non-covalent adducts are scarce. We developed G-quadruplex-based spin-labels containing square-planar Cu(pyridine)4 complexes, covalently incorporated into oligonucleotides, for detecting dimeric structures and measuring intermolecular distances via pulsed dipolar EPR spectroscopy. Furthermore, intercalation of flat molecules into G-quadruplex dimers, resulting in sandwich complexes can be investigated, and previously unknown binding modes discovered. This project applies the transition metal labeling approach, combined with pulsed EPR spectroscopy, to systematically examine an advanced set of structures of non-covalent DNA aggregates, including metal-complexes, supramolecules and DNA-binding proteins. Furthermore, G-quadruplex-based spin labels will be employed to measure distances in other DNA secondary- and tertiary structures such as double strands, bent duplex adducts and G-quadruplex wires. The combination with organic spin labels and ENDOR-active 19F substituents further enhances the applicability of this approach.

DNA G-四链体显示出明显的倾向于形成更高级的结构，例如π-堆叠的二聚体、串珠线和具有芳香族结合配偶体的聚集体，这些与端粒和癌基因的药物靶向有关。确定这些非共价加合物结构的可靠方法是稀缺的。我们开发了基于G-四链体的自旋标记，包含正方形平面Cu（吡啶）4络合物，共价结合到寡核苷酸中，用于检测二聚体结构和通过脉冲偶极EPR光谱测量分子间距离。此外，可以研究扁平分子嵌入G-四链体二聚体中，从而形成夹心复合物，并发现以前未知的结合模式。该项目应用过渡金属标记方法，结合脉冲EPR光谱，系统地研究了一组先进的非共价DNA聚集体的结构，包括金属络合物，超分子和DNA结合蛋白。此外，基于G-四链体的自旋标记将用于测量其他DNA二级和三级结构中的距离，例如双链、弯曲双链体加合物和G-四链体线。与有机自旋标记物和ENDOR活性19 F取代基的组合进一步增强了该方法的适用性。