Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.
Division of Frontier Materials Science and, Center for Advanced Interdisciplinary Research, Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
Angew Chem Int Ed Engl. 2024 Apr 2;63(14):e202319516. doi: 10.1002/anie.202319516. Epub 2024 Feb 12.
We herein report a method for site-selective photo-crosslinking of a DNA duplex. A stilbene pair was introduced into a DNA duplex and a ruthenium complex was conjugated with a triplex-forming oligonucleotide. We demonstrated that [2+2] photocycloaddition of the stilbene pair occurred upon irradiation with visible light when the ruthenium complex was in close proximity due to triplex formation. No reaction occurred when the ruthenium complex was not in proximity to the stilbene pair. The wavelength of visible light used was of lower energy than the wavelength of UV light necessary for direct excitation of stilbene. Quantum chemical calculation indicated that ruthenium complex catalyzed the photocycloaddition via triplet-triplet energy transfer. Site selectivity of this photo-crosslinking system was evaluated using a DNA duplex bearing two stilbene pairs as a substrate; we showed that the site of crosslinking was precisely regulated by the sequence of the oligonucleotide linked to the ruthenium complex. Since this method does not require orthogonal photoresponsive molecules, it will be useful in construction of complex photoresponsive DNA circuits, nanodevices and biological tools.
我们在此报告了一种 DNA 双链的位点选择性光交联方法。将一对二苯乙烯引入 DNA 双链中，并将钌配合物与三聚体形成寡核苷酸缀合。我们证明，当由于三聚体形成而使钌配合物紧密接近时，二苯乙烯对在可见光照射下发生[2+2]光环加成反应。当钌配合物与二苯乙烯对不接近时，不会发生反应。使用的可见光波长的能量低于直接激发二苯乙烯所需的紫外线波长的能量。量子化学计算表明，通过三重态-三重态能量转移，钌配合物催化了光环加成反应。使用带有两个二苯乙烯对的 DNA 双链作为底物评估了这种光交联系统的位点选择性；我们表明，通过与钌配合物连接的寡核苷酸的序列可以精确调节交联的位点。由于这种方法不需要正交光响应分子，因此它将有助于构建复杂的光响应 DNA 电路、纳米器件和生物工具。
