State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Nanoscale. 2015 May 21;7(19):8939-45. doi: 10.1039/c5nr01247c.
AIE (aggregation-induced emission)-active molecules hold promise for the labeling of biomolecules as well as living cells. The study of the binding modes of such molecules to biomolecules, such as nucleic acids and proteins, will shed light on a deeper understanding of the mechanisms of molecular interactions and eventually facilitate the design/preparation of new AIE-active bioprobes. Herein, we studied the binding modes of double-stranded DNA (dsDNA) with two types of synthetic AIE-active molecules, namely, tetraphenylethene-derived dicationic compounds (cis-TPEDPy and trans-TPEDPy) and anthracene-derived dicationic compounds (DSAI and DSABr-C6) using single molecule force spectroscopy (SMFS) and circular dichroism (CD) spectroscopy. The experimental data indicate that DSAI can strongly intercalate into DNA base pairs, while DSABr-C6 is unable to intercalate into DNA due to the steric hindrance of the alkyl side chains. Cis-TPEDPy and trans-TPEDPy can also intercalate into DNA base pairs, but the binding shows strong ionic strength dependence. Multiple binding modes of TPEDPy with dsDNA have been discussed. In addition, the electrostatic interaction enhanced intercalation of cis-TPEDPy with dsDNA has also been revealed.
AIE（聚集诱导发光）活性分子有望用于标记生物分子和活细胞。研究这些分子与生物分子（如核酸和蛋白质）的结合模式，将有助于深入了解分子相互作用的机制，并最终促进新型 AIE 活性生物探针的设计/制备。在此，我们使用单分子力谱（SMFS）和圆二色性（CD）光谱研究了两种合成 AIE 活性分子，即四苯乙烯衍生的二阳离子化合物（顺式-TPEDPy 和反式-TPEDPy）和蒽衍生的二阳离子化合物（DSAI 和 DSABr-C6）与双链 DNA（dsDNA）的结合模式。实验数据表明，DSAI 可以强烈嵌入 DNA 碱基对中，而 DSABr-C6 由于烷基侧链的空间位阻而无法嵌入 DNA。顺式-TPEDPy 和反式-TPEDPy 也可以嵌入 DNA 碱基对，但结合表现出强烈的离子强度依赖性。已经讨论了 TPEDPy 与 dsDNA 的多种结合模式。此外，还揭示了静电相互作用增强了顺式-TPEDPy 与 dsDNA 的插入。
