Karg Beatrice, Funke Andrea, Ficht Anna, Sievers-Engler Adrian, Lämmerhofer Michael, Weisz Klaus
Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Str. 4, 17487 Greifswald (Germany).
Institute of Pharmacy, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany).
Chemistry. 2015 Sep 21;21(39):13802-11. doi: 10.1002/chem.201502118. Epub 2015 Aug 11.
The interactions of a dicarbocyanine dye 3,3'-diethylthiadicarbocyanine, DiSC2(5), with DNA G-quadruplexes were studied by means of a combination of various spectroscopic techniques. Aggregation of excess dye as a result of its positive charge is promoted by the presence of the polyanionic quadruplex structure. Specific high-affinity binding to the parallel quadruplex of the MYC promoter sequence involves stacking of DiSC2(5) on the external G-tetrads; the 5'-terminal tetrad is the favored binding site. Significant energy transfer between DNA and the dye in the UV spectral region is observed upon DiSC2(5) binding. The transfer efficiency strongly depends on the DNA secondary structure as well as on the G-quadruplex topology. These photophysical features enable the selective detection of DNA quadruplexes through sensitized DiSC2(5) fluorescence in the visible region.
通过多种光谱技术相结合的方法，研究了一种双碳菁染料3,3'-二乙基硫代双碳菁（DiSC2(5)）与DNA G-四链体的相互作用。由于其正电荷，过量染料的聚集因多阴离子四链体结构的存在而得到促进。与MYC启动子序列的平行四链体的特异性高亲和力结合涉及DiSC2(5)在外围G-四联体上的堆积；5'-末端四联体是有利的结合位点。在DiSC2(5)结合时，在紫外光谱区域观察到DNA与染料之间有显著的能量转移。转移效率强烈依赖于DNA二级结构以及G-四链体拓扑结构。这些光物理特性使得能够通过可见区域中DiSC2(5)的敏化荧光选择性检测DNA四链体。
