Tajmir-Riahi H A, Langlais M, Savoie R
Department of Chemistry, Laval University, Quebec, Canada.
Nucleic Acids Res. 1988 Jan 25;16(2):751-62. doi: 10.1093/nar/16.2.751.
The interaction of calf-thymus DNA with Cu(II) and Pb(II) ions has been investigated in H2O and D2O solutions at physiological pH, using laser Raman spectroscopy. The results confirm the destabilizing effect of Cu2+ ions, which are shown to bind strongly to the guanine and cytidine bases, perturbing the A-T base pairs and disrupting the double-helical structure of DNA, whose conformation is markedly altered by these interactions. Earlier claims that Pb2+ ions destabilize DNA are not supported by the present study. These ions are found to interact only weakly with the nucleic bases, binding to the N7 position of the guanine bases and also interacting with the A-T pairs. Both types of ions are found to interact with the charged phosphate groups of DNA, although these sites are preferred over the nucleic bases by Pb2+ ions.
利用激光拉曼光谱，在生理pH值下的H₂O和D₂O溶液中研究了小牛胸腺DNA与Cu(II)和Pb(II)离子的相互作用。结果证实了Cu²⁺离子的去稳定作用，表明其与鸟嘌呤和胞嘧啶碱基强烈结合，扰乱A - T碱基对并破坏DNA的双螺旋结构，DNA的构象因这些相互作用而显著改变。本研究不支持早期关于Pb²⁺离子使DNA去稳定的说法。发现这些离子仅与核酸碱基弱相互作用，与鸟嘌呤碱基的N7位置结合并与A - T对相互作用。两种离子都被发现与DNA的带电荷磷酸基团相互作用，不过Pb²⁺离子更倾向于这些位点而非核酸碱基。
