Nucleic acids containing double-headed nucleotides with additional nucleobases attached to the 5â²(S)-position of thymidine through a methylene linker are studied. The additional bases are oriented towards base-base interactions in the minor groove of the DNA-double helix. Two new examples with adenine or cytosine as the additional bases as well as an analogue with a 4N-methylpiperazine in the same position are introduced, and in a combined study with the original double-headed nucleotide containing two thymines, interactions between the additional nucleobases across the minor groove are detected. Finally, a duplex with two thymines in the minor groove is cross-linked using UV irradiation.
本研究对含有双头核苷酸的核酸进行了研究,这些双头核苷酸通过亚甲基连接体在
胸苷的 5â²(S)位上连接了额外的核碱基。附加碱基的方向与 DNA 双螺旋小沟中的碱基相互作用有关。介绍了两个以
腺嘌呤或
胞嘧啶作为附加碱基的新例子,以及一个在相同位置上含有 4N 甲基
哌嗪的类似物,在与含有两个胸腺
嘧啶的原始双头核苷酸的组合研究中,检测到了附加核碱基在小沟中的相互作用。最后,在紫外线照射下,在小凹槽中含有两个
甲状腺素的双链体发生了交联。