聚[d(A-T)]×聚[d(A-T)]的盐诱导构象转变

Salt-induced conformational transition of poly[d(A-T)] X poly[d(A-T)].

作者信息

Vorlícková M, Kypr J, Sklenár V

出版信息

J Mol Biol. 1983 May 5;166(1):85-92. doi: 10.1016/s0022-2836(83)80052-7.

Abstract

Unique chiroptical properties of poly[d(A-T)] X poly[d(A-T)] observed in CsF solutions (Vorlícková et al., 1980) were specified by circular dichroism, ultraviolet light and 31P nuclear magnetic resonance spectroscopy. It was found that up to a 3 M concentration of the salt, caesium cations induced a gradual rearrangement of the polynucleotide double helix during which the phosphodiester bonds in one sequence changed the geometry and the base stacking decreased. At higher CsF concentrations poly[d(A-T)] X poly[d(A-T)] underwent a transition toward a novel conformation which had phosphodiester bonds in both sequences in considerably different non-B-DNA geometries.

摘要

在CsF溶液中观察到的聚[d(A-T)]×聚[d(A-T)]独特的手性光学性质（沃利奇科娃等人，1980年）通过圆二色性、紫外光和31P核磁共振光谱进行了明确。结果发现，在高达3M的盐浓度下，铯阳离子会诱导多核苷酸双螺旋逐渐重排，在此过程中，一个序列中的磷酸二酯键改变了几何形状，碱基堆积减少。在更高的CsF浓度下，聚[d(A-T)]×聚[d(A-T)]会向一种新的构象转变，该构象在两个序列中都具有处于相当不同的非B-DNA几何形状的磷酸二酯键。