Synthesis and photooxidation of oligodeoxynucleotides containing 5-dimethylaminocytosine as an efficient hole-trapping site in the positive-charge transfer through DNA duplexes
作者:Hisatsugu Yamada、Masayuki Kurata、Kazuhito Tanabe、Takeo Ito、Sei-ichi Nishimoto
DOI:10.1039/c2ob06642d
日期:——
hole migrated through the DNA bases and was trapped efficiently at the (DMA)C sites, where an enhanced oxidative strand cleavage occurred by hot piperidine treatment. The (DMA)C radical cation formed by hole transfer may undergo specific hydration and subsequent addition of molecular oxygen, thereby leading to its decomposition followed by a predominant strand cleavage at the (DMA)C site. This remarkable
我们设计和合成了包含5-二甲基氨基胞嘧啶((DMA)C)的DNA双链体,以研究C(5)取代的胞嘧啶碱基对DNA双链体中正电荷(空穴)的转移和捕获的影响。荧光猝灭实验表明,与其他天然核碱基相比,(DMA)C碱基更容易被单电子氧化成自由基阳离子中间体。在对包含(DMA)C的双链体进行光辐照后,注入光敏剂的空穴迁移穿过DNA碱基,并被有效地捕获在(DMA)C位置,在此处通过热哌啶处理产生了增强的氧化链裂解。通过空穴转移形成的(DMA)C自由基阳离子可能会发生特定的水合反应,并随后添加分子氧,从而导致其分解,然后在(DMA)C位点进行主要的链切割。这种非凡的特性表明,修饰的胞嘧啶(DMA)C可以在DNA双链体的正电荷转移中充当有效的空穴捕获位点。