INTERACTIONS OF DNA WITH DIVALENT METAL-IONS .3. EXTENT OF METAL-BINDING - EXPERIMENT AND THEORY
INTERACTIONS OF DNA WITH DIVALENT METAL-IONS .3. EXTENT OF METAL-BINDING - EXPERIMENT AND THEORY
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DOI：
10.1002/bip.360210117
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发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
KEARNS, DR
中科院分区：
文献类型：
--
作者：
GRANOT, J;KEARNS, DR
制备以 Mn2+ 作为唯一抗衡离子的 DNA [来自儿童红细胞]，并通过测量水的质子弛豫增强在各种条件下确定 Mn2+ 结合的程度。每个 DNA 磷酸盐的 Mn2+ 结合总程度为 0.43 .+-。 0.04，与2.8×实验范围内的金属离子浓度无关。 10-5 至 2.1 倍。 10-3M。将曼宁缩合理论的预测与从广义泊松-玻尔兹曼方程的解中获得的有关二价离子与聚电解质结合程度的预测（在存在和不存在一价抗衡离子的情况下）进行了相互比较并与实验结果进行了比较。两种理论方法之间具有良好的一致性，在大范围的单价和二价离子浓度下预测的结合程度方差 < 14%。虽然两种理论方法的预测总体上与实验结果一致，但也注意到了一些差异并讨论了它们可能的起源。
DNA [from children erythrocytes] with Mn2+ as the only counterion was prepared, and the extent of the Mn2+ binding was determined under a variety of conditions through measurements of the proton relaxation enhancement of water. The total extent of Mn2+ binding per DNA phosphate is 0.43 .+-. 0.04, independent of the metal ion concentration in the experimental range of 2.8 .times. 10-5 to 2.1 .times. 10-3M. The predictions of Manning''s condensation theory and those obtained from solution of the generalized Poisson-Boltzmann equation regarding the extent of divalent ion binding to polyelectrolytes, in the presence and absence of monovalent counterions, are compared with one another and with the experimental results. Good agreement between the 2 theoretical approaches is found, with < 14% variance in the predicted extent of binding over a large range of mono- and divalent ion concentrations. While the predictions of both theoretical approaches generally agree with the experimental results, some discrepancies are noted and their possible origins discussed.