Kas'ianenko N A, D'iakonova N E, Frisman E V
Mol Biol (Mosk). 1989 Jul-Aug;23(4):975-82.
The interaction of DNA with divalent metal ions: Ba2+, Mg2+, Mn2+, Ni2+, Cu2+ in solutions at different ionic strengths mu was investigated. The combination of following methods: flow birefringence, viscometry, UV-spectroscopy and circular dichroism made possible to follow the state of the secondary and tertiary structure of the DNA molecule during its interaction with ions. The presence of divalent ions in solution affects the hydrodynamic properties of DNA only at low mu. At high mu the difference in the action of mono- and divalent ions disappears. The persistence length of DNA does not change during the experiment. It is shown that the Mg2+ and Ba2+ ions interact only with phosphate groups of DNA but Mn2+, Ni2+, Cu2+ ions interact also with the nitrogen bases of the macromolecule.
研究了DNA与二价金属离子：Ba2+、Mg2+、Mn2+、Ni2+、Cu2+在不同离子强度μ的溶液中的相互作用。流动双折射、粘度测定、紫外光谱和圆二色性等方法的结合使得在DNA分子与离子相互作用过程中跟踪其二级和三级结构状态成为可能。溶液中二价离子的存在仅在低μ时影响DNA的流体动力学性质。在高μ时，单价和二价离子作用的差异消失。DNA的持久长度在实验过程中不变。结果表明，Mg2+和Ba2+离子仅与DNA的磷酸基团相互作用，而Mn2+、Ni2+、Cu2+离子也与大分子的氮碱基相互作用。
