INTERACTION OF METAL IONS WITH POLYNUCLEOTIDES AND RELATED COMPOUNDS .12. RELATIVE EFFECT OF VARIOUS METAL IONS ON DNA HELICITY
INTERACTION OF METAL IONS WITH POLYNUCLEOTIDES AND RELATED COMPOUNDS .12. RELATIVE EFFECT OF VARIOUS METAL IONS ON DNA HELICITY
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DOI：
10.1021/ja01028a024
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发表时间：
1968-01-01
影响因子：
15
通讯作者：
SHIN, YA
中科院分区：
文献类型：
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作者：
EICHHORN, GL;SHIN, YA
先前已经证明了Cu（II）和Zn（II）在适当条件下引起DNA双螺旋的解旋和重绕的能力。本研究揭示了其他二价金属离子对DNA具有类似的作用，并且可以按照指示其对DNA结构的影响程度的顺序放置，如下：Mg（II），Co（II），Ni（II），Mn（II），Zn（II），Cd（II），Cu（II）。这个顺序是从下列现象中推导出来的。(1)DNA的解链温度（7%）随着系列左边金属浓度的增加而增加，而右边金属的7%通过最大值，最大值发生在最右边的最低浓度。(2)最左边的Mg（II）不能引起任何可检测到的双螺旋的重绕; Co、Ni和Mn产生部分重绕，而最右边的金属使DNA完全复性。(3)这些金属使DNA的最大吸收峰从左向右移动。通过这三个标准，金属在相同序列中的位置很容易解释为它们结合磷酸盐和杂环“碱”位点的能力，其中“碱”与磷酸盐的亲和力的比率从左到右增加。金属离子与多核苷酸上各种电子供体位点反应的能力受到了相当大的关注。有两个主要的相互作用位点，核糖磷酸骨架的磷酸部分和碱基上的电子供体基团。2，3两种类型的相互作用带来了一些相当有趣的结果。与磷酸盐的反应意味着有序结构的稳定，4-8
The ability of Cu (II) and Zn (II) to bring about the unwinding and rewinding of the DNA double helix under appropriate conditions has been previously demonstrated. The present study reveals that other divalent metal ions have similar effects upon DNA and can be placed in a sequence that indicates the magnitude of their influence on DNA structure, as follows: Mg (II), Co (II), Ni (II), Mn (II), Zn (II), Cd (II), Cu (II). This sequence is deduced from the following phenomena.(1) The melting temperature (7%) of DNA increases with increasing metal concentration for the metalsat the left of the series, whereas 7% passes through a maximum for the metals to the right, the maximum occurring at lowest concentration at the far right.(2) Mg (II) at the far left cannot induce any detectable rewindingof the double helix; Co, Ni, and Mn produce partial rewinding, whereas the metals on the ex-treme right bring about complete renaturation of DNA.(3) These metals produce an increasing shift in the ab-sorption maximum ofDNA, fromleft to right. The placement of the metals in the same sequence by these three criteria is readily explained by their ability to bind both phosphateand heterocyclic “base” sites with the ratio of affinity for “base” to phosphate increasing from left to right. he ability of metal ions to react with a variety of electron-donor sites on polynucleotides has received considerable attention. There are two main sites of interaction, the phosphate moieties of the ribose phosphate backbone, and the electron-donor groups on the bases. 2, 3 Two types of interaction carry with them some rather interesting consequences. Reaction with phosphate means stabilization of orderedstructures, 4-8