物理化学学报 >> 1992, Vol. 8 >> Issue (02): 207-211.doi: 10.3866/PKU.WHXB19920213

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不同价态金属离子对DNA构象的影响

李安之; 丁玫; 于海鹰; 章江英   

  1. 南开大学物理系，天津 300071
  • 收稿日期:1990-10-22 修回日期:1991-05-27 发布日期:1992-04-15
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The Effect of Metal Ions of Differentvalences on Conformation of DNA Molecules

Li An-Zhi; Ding Mei; Yu Hai-Ying; Zhang Jiang-Ying   

  1. Department of Physics, Nankai University, Tianjin 300071
  • Received:1990-10-22 Revised:1991-05-27 Published:1992-04-15
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摘要： 用紫外分光光度法研究了不同价态金属离子对DNA大分子溶液构象的影响。研究结果显示: 金属离子与DNA的作用使DNA溶液的紫外吸收值下降, 即呈现减色效应, 同时减色效应的强弱与金属离子的价态有关。随着价态升高, 减色效应增强。由此说明, 金属离子与DNA的作用使DNA的构象趋于缩拢; 且随着金属离子价态升高, 缩拢程度增强, 甚至产生缩合。还用现代多聚电解质理论对以上现象进行了讨论, 结果是令人满意的。

关键词: 构象, 减色效应, 缩合, 挠性, 紫外分光光度法

Abstract: The effect of metal ions of different valences on the conformation of DNA molecules by UV spectra has been studied. The result shows that a hypochromicity occurs at 257 nm after adding metal ions, and the degree of hypochromicity depends on the valence of metal ions. The higher the valence of metal ion, the stronger the hypochromicity. It follows that interactions of metal ions with DNA molecules cause contraction of DNA conformation. The higher the valence of the metal ion, the stronger the effect, eventually, DNA condensation may be induced. The phenomena has been disscussed according to Modern Polyelectrolyte Theory, and the result is satisfactory.

Key words: Conformation, Hypochromicity, Condensation, Flexibility, UV spectra