Haasnoot C A, den Hartog J H, de Rooij J F, van Boom J H, Altona C
Nucleic Acids Res. 1980 Jan 11;8(1):169-81. doi: 10.1093/nar/8.1.169.
A comparative nuclear magnetic resonance study of the hydrogen-bonded imino protons in a series of synthetic DNA fragments is presented. The fragments ATCCTA(Tn)TAGGAT are in principle capable of forming either a self-complementary hairpin loop structure (monomer form) or an interior loop structure (dimeric form). It has been shown, that for n = 1 only the dimer structure is present in aqueous solution, whereas the exclusive existence of the hairpin loop structure is indicated for n = 3, 4 & 5. Surprisingly, for n = 2 two different structures appear to be present in solution. Concentration studies show that both monomers and dimers exist side by side in this case. Hairpins as well as interior loops form extra "melting sites" in addition to the wellknown fraying phenomenon at the terminus of the double helix.
本文介绍了一系列合成DNA片段中氢键亚氨基质子的比较核磁共振研究。片段ATCCTA(Tn)TAGGAT原则上能够形成自互补发夹环结构(单体形式)或内环结构(二聚体形式)。研究表明,当n = 1时,水溶液中仅存在二聚体结构,而当n = 3、4和5时,则表明仅存在发夹环结构。令人惊讶的是,当n = 2时,溶液中似乎存在两种不同的结构。浓度研究表明,在这种情况下,单体和二聚体并存。除了双螺旋末端众所周知的解链现象外,发夹环和内环还形成了额外的“解链位点”。