Anthraquinone Photonucleases: Mechanisms for GG-Selective and Nonselective Cleavage of Double-Stranded DNA
作者:David T. Breslin、Gary B. Schuster
DOI:10.1021/ja953714w
日期:1996.1.1
character and reacts only by electrontransfer. Spectroscopic evidence indicates that both quinones bind to double-stranded DNA by intercalation with essentially the same affinity. Picosecond time-resolved laser spectroscopy shows that single electrontransfer from the DNA bases to either bound quinone occurs rapidly and to the same extent. Irradiation of either intercalated 2AQA2(HEt2) or 2AQC2(HEt2)
蒽醌衍生物 2AQA2(HEt2) 和 2AQC2(HEt2) 作为启动 DNA 切割的光活化剂进行了检查。取代基控制蒽醌的最低激发态的电子构型。2AQC2(HEt2) 具有最低的 nπ* 激发态,可以通过电子转移或氢原子提取进行反应。2AQC2(HEt2) 具有最低激发态 ππ* 或分子内电荷转移特性,仅通过电子转移发生反应。光谱证据表明,两种醌都通过嵌入以基本相同的亲和力与双链 DNA 结合。皮秒时间分辨激光光谱显示,从 DNA 碱基到任一结合醌的单电子转移发生迅速且程度相同。辐照嵌入的 2AQA2(HEt2) 或 2AQC2(HEt2),然后用热哌啶处理,可在 GG 步骤的 5'-G 处同样有效地切割 DNA。这些发现表明电子从 DNA 碱基转移到激发的醌是...