Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany.
Beilstein J Org Chem. 2014 Sep 9;10:2139-44. doi: 10.3762/bjoc.10.221. eCollection 2014.
The imidazole-Ag(I)-imidazole base pair is one of the best-investigated artificial metal-mediated base pairs. We show here that its stability can be further improved by formally replacing the imidazole moiety by a 2-methylimidazole or 4-methylimidazole moiety. A comparison of the thermal stability of several double helices shows that the addition of one equivalent of Ag(I) leads to a 50% larger increase in the melting temperature when a DNA duplex with methylated imidazole nucleosides is applied. This significant effect can likely be attributed to a better steric shielding of the metal ion within the metal-mediated base pair.
咪唑-Ag（I）-咪唑碱基对是研究最深入的人工金属介导碱基对之一。我们在这里表明，通过将咪唑部分正式替换为 2-甲基咪唑或 4-甲基咪唑部分，可以进一步提高其稳定性。对几种双螺旋体的热稳定性进行比较表明，当应用含有甲基化咪唑核苷的 DNA 双链体时，添加一个当量的 Ag（I）可使熔点提高 50%。这种显著的效果可能归因于金属离子在金属介导碱基对中更好的空间位阻屏蔽。
