DNA 高阶结构的自组装特性和多样性使可编程工具能够用于在分子水平上构建算法。然而,基于 DNA 的可编程工具的实用性受到与天然核酸的低正交性的阻碍,特别是在复杂的分子系统中。为了应对这一挑战,我们在此报告了通过使用非自然碱基对 (UBP) 形成对 DNA 自组装的正交调节。我们新设计的 UBP An N : Sy N是结合抗和不寻常的顺式糖苷构象形成的,具有高热稳定性和选择性。此外,一个C作为一种 pH 敏感的人工核碱基,在弱酸性条件(pH 6.0)下与胞嘧啶形成强碱基对。正交An N : Sy N碱基对作为杂交链反应的触发器,以提供长切口双链 DNA(约 1000 个碱基对)。这项工作代表了正交 DNA 自组装的第一个例子,它对自然的四字母字母 DNA 触发器没有反应,并扩展了在复杂环境中工作的可编程工具的类型。
Synthesis of 8-(2′-deoxy-β-d-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one
摘要:
We describe the synthetic strategy of a purine like nucleoside and the separation of an epimeric mixture. The nucleoside possesses two proton acceptor sites, and they are expected to provide a new base pairing pattern and new protein-DNA targeting. These isomeric structures were determined by conducting an NOE experiment. (C) 2007 Elsevier Ltd. All rights reserved.
Novel 5-aza-7-deaza isosteres of the anti-HIV compounds, dideoxyinosine (ddI) and dideoxyguanosine (ddG), have been prepared by glycosylation of the corresponding isosteric bases with appropriately tailored dideoxyribose components. The glycosylation reactions were regiospecific and the position of glycosylation was established by UV and high-field NMR data. However, attempted preparation of the 3-deaza-5-aza isostere of dideoxyinosine led to a different regioisomer, a ring-extended dideoxycytidine analogue, whose structure was established by X-ray crystallographic data. The 5-aza-7-deaza isosteres of ddI and ddG were more stable with respect to hydrolytic cleavage than ddI and ddG.