Structural Basis for Bifunctional Zinc(II) Macrocyclic Complex Recognition of Thymine Bulges in DNA
作者:Imee Marie A. del Mundo、Kevin E. Siters、Matthew A. Fountain、Janet R. Morrow
DOI:10.1021/ic3004245
日期:2012.5.7
10-tetraazacyclododecane (cy4q) binds selectively to thymine bulges in DNA and to a uracil bulge in RNA. Binding constants are in the low-micromolar range for thymine bulges in the stems of hairpins, for a thymine bulge in a DNA duplex, and for a uracil bulge in an RNA hairpin. Binding studies of Zn(cy4q) to a series of hairpins containing thymine bulges with different flanking bases showed that the complex
1-(4-喹啉基)甲基-1,4,7,10-四氮杂环十二烷(cy4q)的锌(II)络合物选择性结合DNA中的胸腺嘧啶凸起和RNA中的尿嘧啶凸起。对于发夹茎中的胸腺嘧啶隆起,在DNA双链体中的胸腺嘧啶隆起和在RNA发夹中的尿嘧啶隆起,结合常数在低微摩尔范围内。Zn(cy4q)与一系列含有不同侧翼碱基的胸腺嘧啶凸起的发夹的结合研究表明,该复合物对胸腺嘧啶凸起与邻近的嘌呤具有中等选择性。最牢固结合的Zn(cy4q)–DNA胸腺嘧啶凸出加合物的解离常数比具有完全互补茎的相似序列或含有胞嘧啶,鸟嘌呤或腺嘌呤的凸出更紧密100倍。为了探讨悬垂基团的作用,另外三种含有1,4,7,N,N-二甲基萘-1-胺(dsc)。Zn(cybp)复合物以适度的亲和力结合,但对胸腺嘧啶凸起的DNA发夹和缺乏凸起的DNA的选择性很小。同样,Zn(dsc)与胸腺嘧啶凸起和具有完全互补茎的发夹均弱结合。cy2q的锌(II)配合物具有与Zn