Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie & NRW Graduate School of Chemistry, Corrensstrasse 28/30, 48149 Münster (Germany).
Angew Chem Int Ed Engl. 2015 Mar 16;54(12):3603-6. doi: 10.1002/anie.201411931. Epub 2015 Jan 28.
The first parallel-stranded DNA duplex with Hoogsteen base pairing that readily incorporates an Ag(+) ion into an internal mispair to form a metal-mediated base pair has been created. Towards this end, the highly stabilizing 6 FP-Ag(+)-6 FP base pair comprising the artificial nucleobase 6-furylpurine (6 FP) was devised. A combination of temperature-dependent UV spectroscopy, CD spectroscopy, and DFT calculations was used to confirm the formation of this base pair. The nucleobase 6 FP is capable of forming metal-mediated base pairs both by the Watson-Crick edge (i.e. in regular antiparallel-stranded DNA) and by the Hoogsteen edge (i.e. in parallel-stranded DNA), depending on the oligonucleotide sequence and the experimental conditions. The 6 FP-Ag(+)-6 FP base pair within parallel-stranded DNA is the most strongly stabilizing Ag(+)-mediated base pair reported to date for any type of nucleic acid, with an increase in melting temperature of almost 15 °C upon the binding of one Ag(+) ion.
已经创建了第一个具有 Hoogsteen 碱基配对的平行双链 DNA，它可以轻易地将 Ag(+)离子纳入内部错配，形成金属介导的碱基对。为此，设计了由人工碱基 6-呋喃基嘌呤 (6-FP) 组成的高度稳定的 6-FP-Ag(+)-6-FP 碱基对。使用温度依赖的 UV 光谱、CD 光谱和 DFT 计算的组合来确认该碱基对的形成。6-FP 碱基既能通过 Watson-Crick 边缘（即在常规反平行双链 DNA 中），也能通过 Hoogsteen 边缘（即在平行双链 DNA 中）形成金属介导的碱基对，这取决于寡核苷酸序列和实验条件。在平行双链 DNA 中，6-FP-Ag(+)-6-FP 碱基对是迄今为止报道的任何类型核酸中最强稳定的 Ag(+)介导碱基对，结合一个 Ag(+)离子后，熔点温度升高近 15°C。
