Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba 305-8566, Japan.
Bioorg Med Chem Lett. 2013 Nov 15;23(22):6123-6. doi: 10.1016/j.bmcl.2013.09.017. Epub 2013 Sep 14.
We have synthesized a nonnucleoside amidite block of dansyl fluorophore to prepare dansyl-modified oligonucleotides (ONTs). The fluorescence intensities of dansyl-ONT specifically increased by the presence of adjacent guanosine residues but, significantly reduced in a dansyl-flipping duplex. These changes were caused by solvatochromism effect due to the number of guanine which is hydrophobic functional group and the external environment of dansyl group. The fluorescence intensities could be plotted as a function of the ONTs concentrations and the increase in the fluorescence was observed to equimolar concentrations of target DNA. This duplex exhibited higher melting temperature relative to the corresponding duplexes containing other base pairs. Similar changes in fluorescence could be detected upon hybridization with complementary RNAs. Thus, the dansyl-modified ONTs provide sequence specific fluorescent probe of DNA and RNA.
我们合成了一种非核苷酰胺块的丹磺酰荧光团，以制备丹磺酰修饰的寡核苷酸（ONTs）。丹磺酰-ONT 的荧光强度特异性地增加了相邻鸟嘌呤残基的存在，但在丹磺酰翻转双链体中显著降低。这些变化是由于溶剂化变色效应引起的，这是由于鸟嘌呤的数量，鸟嘌呤是疏水性官能团，丹磺酰基的外部环境。荧光强度可以作为 ONTs 浓度的函数来绘制，并且观察到在等摩尔浓度的靶 DNA 时荧光强度增加。与含有其他碱基对的相应双链体相比，该双链体表现出更高的熔点。与互补 RNA 杂交时也可以检测到类似的荧光变化。因此，丹磺酰修饰的 ONTs 提供了 DNA 和 RNA 的序列特异性荧光探针。
