Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, University of Münster, Heisenbergstrasse 11, 48149, Münster, Germany.
Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastrasse 7, 49069, Osnabrück, Germany.
Chemistry. 2021 May 6;27(26):7453-7466. doi: 10.1002/chem.202005199. Epub 2021 Mar 18.
The Watson-Crick coding system depends on the molecular recognition of complementary purine and pyrimidine bases. Now, the construction of hybrid DNAs with Watson-Crick and purine-purine base pairs decorated with dendritic side chains was performed. Oligonucleotides with single and multiple incorporations of 5-aza-7-deaza-2'-deoxyguanosine, its tripropargylamine derivative, and 2'-deoxyisoguanosine were synthesized. Duplex stability decreased if single modified purine-purine base pairs were inserted, but increased if pyrene residues were introduced by click chemistry. A growing number of consecutive 5-aza-7-deazaguanine-isoguanine base pairs led to strong stepwise duplex stabilization, a phenomenon not observed for the guanine-isoguanine base pair. Spacious residues are well accommodated in the large groove of purine-purine DNA tracts. Changes to the global helical structure monitored by circular dichroism spectroscopy show the impact of functionalization to the global double-helix structure. This study explores new areas of molecular recognition realized by purine base pairs that are complementary in hydrogen bonding, but not in size, relative to canonical pairs.
沃森-克里克编码系统依赖于互补嘌呤和嘧啶碱基的分子识别。现在，已经构建了具有沃森-克里克和带有树枝状侧链修饰的嘌呤-嘌呤碱基对的杂交 DNA。合成了具有单取代和多取代的 5-氮杂-7-脱氮-2'-脱氧鸟嘌呤、其三炔丙基衍生物和 2'-脱氧异鸟嘌呤的寡核苷酸。如果插入单个修饰的嘌呤-嘌呤碱基对，双链体稳定性会降低，但如果通过点击化学引入芘残基，则会增加。越来越多的连续 5-氮杂-7-脱氮鸟嘌呤-异鸟嘌呤碱基对导致强逐步双链体稳定化，而对于鸟嘌呤-异鸟嘌呤碱基对则没有观察到这种现象。大的空间残基可以很好地容纳在嘌呤-嘌呤 DNA 片段的大沟中。通过圆二色性光谱监测到的全局螺旋结构变化表明了功能化对全局双螺旋结构的影响。本研究探索了通过氢键互补但大小不互补的嘌呤碱基对实现的分子识别的新领域。
