RNAG4作为G4结构的一个完整分支,与常见的DNAG4相比,与配体具有不同的相互作用,因此RNAG4/配体相互作用的研究可能被认为是提高G4/配体系统生物传感性能的新突破。在这项研究中,我们比较探讨了RNAG4和DNAG4与配体相互作用的结构和功能机制,血红素和硫黄素T(ThT),利用经典的PS2。M序列作为模子。我们发现,尽管RNAG4/血红素系统的催化性能低于DNAG4/血红素,RNAG4/ThT荧光系统与DNAG4/ThT相比有显著改善(2~3倍),腺嘌呤修饰可以进一步增强信号传导。Further,通过探索RNAG4和ThT之间的相互作用,我们认为,与DNAG4/ThT的单分子结合相比,RNAG4和ThT以双分子模式堆叠,因此更强烈地限制了ThT激发态的结构自旋。Further,RNAG4/ThT比DNAG4/ThT表现出更高的环境耐受性和更低的离子依赖性。最后,我们采用RNAG4/ThT作为高灵敏度无标记荧光信号输出系统,对BCR-ABLe13a2和e14a2亚型进行原位成像.总的来说,本研究通过系统的RNAG4/配体相互作用研究,成功筛选出高性能的RNAG4生物传感系统,有望为后续G4/配体研究提供有前景的参考。
RNA G4, as an integral branch of G4 structure, possesses distinct interactions with ligands compared to the common DNA G4, thus the investigation of RNA G4/ligand interactions might be considered as a fresh breakthrough to improve the biosensing performance of G4/ligand system. In this study, we comparatively explored the structural and functional mechanisms of RNA G4 and DNA G4 in the interaction with ligands, hemin and thioflavin T (ThT), utilizing the classical PS2.M sequence as a model. We found that although the catalytic performance of RNA G4/hemin system was lower than DNA G4/hemin, RNA G4/ThT fluorescence system exhibited a significant improvement (2∼3-fold) compared to DNA G4/ThT, and adenine modification could further enhance the signaling. Further, by exploring the interaction between RNA G4 and ThT, we deemed that RNA G4 and ThT were stacked in a bimolecular mode compared to single-molecule binding of DNA G4/ThT, thus more strongly limiting the structural spin in ThT excited state. Further, RNA G4/ThT displayed higher environmental tolerance and lower ion dependence than DNA G4/ThT. Finally, we employed RNA G4/ThT as a highly sensitive label-free fluorescent signal output system for in situ imaging of isoforms BCR-ABL e13a2 and e14a2. Overall, this study successfully screened a high-performance RNA G4 biosensing system through systematic RNA G4/ligands interaction studies, which was expected to provide a promising reference for subsequent G4/ligand research.