Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
J Am Chem Soc. 2020 Dec 30;142(52):21640-21644. doi: 10.1021/jacs.0c11437. Epub 2020 Dec 18.
A 5-carboxyuracil (caU) nucleobase was found to pair not only with A (caU-A) by hydrogen bonding but also with other DNA nucleobases by metal coordination bonding. Metal-dependent formation of caU-Cu-caU, caU-Hg-T, caU-Ag-C, and caU-Cu-G pairs was demonstrated by duplex melting analysis and mass spectrometry. The duplexes containing caU-X (X = caU, T, C, and G) were significantly stabilized in the presence of the corresponding metal ions, while the DNA duplexes containing the caU-A pairs were destabilized by the addition of Cu. These results suggest that the hybridization partner of caU-containing DNA strands can be altered by metal complexation. As a result, this study provides a new direction to integrate caU nucleobases to construct diverse metallo-DNA supramolecules and metal-responsive DNA devices.
5-羧基尿嘧啶（caU）碱基不仅可以通过氢键与 A（caU-A）配对，还可以通过金属配位键与其他 DNA 碱基配对。通过双链体熔化分析和质谱法证实了 caU-Cu-caU、caU-Hg-T、caU-Ag-C 和 caU-Cu-G 配对是金属依赖性形成的。在相应金属离子存在下，含有 caU-X（X=caU、T、C 和 G）的双链体显著稳定，而含有 caU-A 对的 DNA 双链体则因加入 Cu 而不稳定。这些结果表明，含有 caU 的 DNA 链的杂交伙伴可以通过金属络合来改变。因此，本研究为整合 caU 碱基构建多样化的金属-DNA 超分子和金属响应 DNA 器件提供了新的方向。
