汞（II）结合导致聚[d（T-G）.d（C-A）]手性的变化：圆二色性（CD）研究。

Changes in poly[d(T-G).d(C-A)] chirality due to Hg(II)-binding: circular dichroism (CD) studies.

作者信息

Gruenwedel D W, Cruikshank M K

机构信息

Department of Food Science and Technology, University of California, Davis 95616.

出版信息

J Inorg Biochem. 1991 Jul;43(1):29-36. doi: 10.1016/0162-0134(91)84066-i.

DOI:10.1016/0162-0134(91)84066-i

PMID:1940900

Abstract

The conformation of poly[d(T-G).d(C-A)] in aqueous solution (0.1 M NaClO4, 5 mM cacodylic acid buffer, pH 6.9) was studied by circular dichroism (CD) spectroscopy in the ultraviolet. The conformation of the polynucleotide, as reflected by its chiroptical signature, changes in a highly cooperative fashion in the presence of Hg(ClO4)2. The CD changes signal transitions first from the B to a modified B-state (B*), or to a non-B structure termed X, and finally to a form that is presumably Z. The alterations are totally reversible subsequent to the removal of mercury with the help of a suitable complexing agent such as sodium cyanide, indicating that mercuration does not disrupt Watson-Crick hydrogen bonding to any extent.

摘要

通过紫外圆二色光谱（CD）研究了聚[d（T-G）·d（C-A）]在水溶液（0.1 M高氯酸钠，5 mM二甲胂酸缓冲液，pH 6.9）中的构象。在Hg(ClO4)2存在下，多核苷酸的构象（由其手性光学特征反映）以高度协同的方式发生变化。CD变化信号首先从B态转变为修饰的B态（B*），或转变为一种称为X的非B结构，最终转变为可能是Z的形式。在使用合适的络合剂（如氰化钠）除去汞之后，这些变化是完全可逆的，这表明汞化在任何程度上都不会破坏沃森-克里克氢键。