Purine-Derived Nitroxides for Noncovalent Spin-Labeling of Abasic Sites in Duplex Nucleic Acids
作者:Nilesh R. Kamble、Snorri Th. Sigurdsson
DOI:10.1002/chem.201705410
日期:2018.3.15
isoindoline‐derived spin labels showed extensive or full binding to abasic sites in RNA duplexes, whereas the TEMPO‐derived spin labels showed limited binding. An adenine‐derived spin label (5) bound fully at low temperature to abasic sites in both DNA and RNA duplexes when paired with thymine and uracil, respectively, complementing the previously described guanine‐derived spin label Ǵ, which binds efficiently
制备了一系列基于嘌呤的自旋标记物,用于通过氢键结合至相对链上的孤儿碱基以及与侧翼碱基的π堆积相互作用,对双链核酸的无碱基位点进行非共价自旋标记。1,1,3,3-四甲基异吲哚-2-基氧基和2,2,6,6-四甲基哌啶-1-基氧基(TEMPO)与嘌呤的C2或C6位共轭,产生鸟嘌呤,腺嘌呤或2,6-二氨基嘌呤。源自异吲哚啉的自旋标记物显示出与RNA双链体中无碱基位点的广泛或完全结合,而来自TEMPO的自旋标记物显示出有限的结合。腺嘌呤衍生的自旋标签(5)分别与胸腺嘧啶和尿嘧啶配对时,在低温下完全结合到DNA和RNA双链体中的无碱基位点,从而补充了先前描述的鸟嘌呤衍生的自旋标记Ǵ,该标记有效地与相反的胞嘧啶结合。化合物ǵ也显示结合在DNA-RNA杂交脱碱基位点,无论是在DNA或所述RNA链。Ǵ与RNA的无碱基位点结合后,仅显示出较小的侧翼序列效应。当脱碱基位点被放置在靠近RNA双链体的端部时,自旋标记的亲和力ǵ降低;