胞嘧啶质子化和阳离子对平行DNA三链体家族热力学性质的影响

Effect of cytosine protonation and cation on thermodynamic properties of parallel DNA triplex family.

作者信息

Wu P, Hara H, Kawamoto Y, Sugimoto N

机构信息

High Technology Research Center, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.

出版信息

Nucleic Acids Res Suppl. 2001(1):39-40. doi: 10.1093/nass/1.1.39.

DOI:10.1093/nass/1.1.39

PMID:12836253

Abstract

The conformational and thermodynamic properties of three modified parallel triplexes, which have the same base composition but differ in the orientation of the Hoogsteen third strand with respect to the core duplex, were comparatively discussed. The results show that the intermolecular triplex is unstable relatively to the intramolecular triplex and the thermodynamic properties are slightly dependent on the 3' or/and 5' junctions. Furthermore, mono- and divalent cations compete each other in stabilizing the triple helix structure and a higher concentration of the monovalent cation would shield the effect of divalent cations on the triplex stability.

摘要

对三种修饰的平行三链体的构象和热力学性质进行了比较讨论，这三种三链体具有相同的碱基组成，但Hoogsteen第三条链相对于核心双链体的方向不同。结果表明，分子间三链体相对于分子内三链体是不稳定的，并且热力学性质略微依赖于3'或/和5'连接。此外，单价和二价阳离子在稳定三螺旋结构方面相互竞争，较高浓度的单价阳离子会屏蔽二价阳离子对三链体稳定性的影响。