Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany.
Humboldt Universität zu Berlin, Department Chemie, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
Angew Chem Int Ed Engl. 2017 Jan 2;56(1):384-388. doi: 10.1002/anie.201608712. Epub 2016 Nov 28.
A 13mer DNA duplex containing the artificial 4-aminophthalimide:2,4-diaminopyrimidine (4AP:DAP) base pair in the central position was characterized by optical and NMR spectroscopy. The fluorescence of 4AP in the duplex has a large Stokes shift of Δλ=124 nm and a quantum yield of Φ =24 %. The NMR structure shows that two interstrand hydrogen bonds are formed and confirms the artificial base pairing. In contrast, the 4-N,N-dimethylaminophthalimide moiety prefers the syn conformation in DNA. The fluorescence intensity of this chromophore in DNA is very low and the NMR structure shows no significant interaction with DAP. Primer-extension experiments with DNA polymerases showed that not only is the 4AP C nucleotide incorporated at the desired position opposite DAP in the template, but also that the polymerase is able to progress past this position to give the full-length product. The observed selectivity supports the NMR results.
一段包含人工 4-氨基邻苯二甲酰亚胺：2,4-二氨基嘧啶（4AP：DAP）碱基对的 13 mer DNA 双链体通过光学和 NMR 光谱进行了表征。双链体中 4AP 的荧光具有 124nm 的大斯托克斯位移Δλ和 24%的量子产率Φ。NMR 结构表明形成了两条链间氢键，并证实了人工碱基配对。相比之下，4-N，N-二甲基邻苯二甲酰亚胺部分在 DNA 中更喜欢顺式构象。该生色团在 DNA 中的荧光强度非常低，并且 NMR 结构显示与 DAP 没有明显相互作用。DNA 聚合酶的引物延伸实验表明，不仅 4AP C 核苷酸在模板中与 DAP 相对应的位置被掺入，而且聚合酶能够越过该位置生成全长产物。观察到的选择性支持 NMR 结果。
