Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149, Münster, Germany.
Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, West China Hospital, Sichuan University, 610041, Sichuan, P. R. China.
Chemistry. 2020 Nov 2;26(61):13973-13989. doi: 10.1002/chem.202002765. Epub 2020 Sep 30.
Heterochiral DNA with hydrogen-bonded and silver-mediated base pairs have been constructed using complementary strands with nucleosides with α-d or β-d configuration. Anomeric phosphoramidites were employed to assemble the oligonucleotides. According to the T values and thermodynamic data, the duplex stability of the heterochiral duplexes was similar to that of homochiral DNA, but mismatch discrimination was better in heterochiral DNA. Replacement of purines by 7-deazapurines resulted in stable parallel duplexes, thereby confirming Watson-Crick-type base pairing. When cytosine was facing cytosine, thymine or adenine residues, duplex DNA formed silver-mediated base pairs in the presence of silver ions. Although the CD spectra of single strands with α-d configuration display mirror-like shapes to those with the β-d configuration, the CD spectra of the hydrogen-bonded duplexes and those with a limited number of silver pairs show a B-type double helix almost indistinguishable from natural DNA. Nonmelting silver ion-DNA complexes with entirely different CD spectra were generated when the number of silver ions was equal to the number of base pairs.
已使用具有 α-D 或 β-D 构型的核苷构建了具有氢键和银介导碱基对的异手性 DNA。采用糖基磷酸酰胺将寡核苷酸进行组装。根据 T 值和热力学数据，异手性双链体的双链体稳定性与同手性 DNA 相似，但异手性 DNA 中的错配识别更好。嘌呤被 7-脱氮嘌呤取代后形成稳定的平行双链体，从而证实了 Watson-Crick 型碱基配对。当胞嘧啶面对胞嘧啶、胸腺嘧啶或腺嘌呤残基时，双链 DNA 在银离子存在下形成银介导的碱基对。尽管具有 α-D 构型的单链的 CD 光谱与其 β-D 构型的光谱镜像相似，但氢键双链体和具有有限数量银对的那些的 CD 光谱显示出几乎与天然 DNA 无法区分的 B 型双螺旋。当银离子的数量等于碱基对的数量时，生成了具有完全不同 CD 光谱的非熔融银离子-DNA 配合物。
