Influence of alkali cation nature on structural transitions and reactions of biopolyelectrolytes
Influence of alkali cation nature on structural transitions and reactions of biopolyelectrolytes
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DOI：
10.1021/bm000042f
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发表时间：
2000-12-01
影响因子：
6.2
通讯作者：
Nordenskiöld, L
中科院分区：
文献类型：
--
作者：
Korolev, N;Nordenskiöld, L
本文给出了一个一般的热力学分析，描述了不同性质但相同化合价的化合物如何影响一般形式PA（1）的相变和反应。B-1-M+ --> PA（2）.B2M+ +（B-1 --> B-2）M+.这里PA（1）和PA（2）是聚阴离子的两种不同状态或结构形式，B-1和B-2分别是与聚阴离子PA（1）和PA（2）化学键合的M+离子的数目。两种抗衡离子M1（+）和M2（+）对该平衡的具体影响可以简单地与它们的选择性常数的商D-2（M1）M2/D-1（M1）M2相关。对于聚离子状态1和2。我们分析了不同的单价抗衡离子（特别是钠和钾）如何影响质子交换反应和转化，例如，DNA螺旋-卷曲转变。先前的实验结果之间的竞争DNA和合成的聚阴离子，聚（甲基丙烯酸），结合到合成的聚阳离子，聚（N-乙基乙烯基吡啶），已经研究了相对于钠和钾离子的特异性，使用我们的模型。我们还讨论了DNA-组蛋白的拆卸/组装反应建模为两个聚阴离子的竞争结合的聚阳离子。
A general thermodynamic analysis is presented, describing how counterion species of different nature, but the same valency, influence polyelectrolyte transformations and reactions of the general form: PA(1). B-1-M+ --> PA(2).B2M+ + (B-1 --> B-2)M+. Here PA(1) and PA(2) are two different states or structural forms of a polyanion, B-1 and B-2 are the number of M+ ions thermodynamically bound to the polyanions PA(1) and PA(2), respectively. The specific effects of the two counterions, M1(+) and M2(+), on this equilibrium can be simply related to the quotient of their selectivity constants, D-2(M1)M2/D-1(M1)M2. for the polyion states 1 and 2. We analyze how different monovalent counterions (particularly, sodium and potassium) affect polyelectrolyte reactions and transformations such as, e.g., the DNA helix-coil transition. Previous experimental results on the competition between DNA and the synthetic polyanion, poly(methacrylic acid), for binding to the synthetic polycation, poly(N-ethylvinylpyridinium), has been investigated with respect to sodium and potassium ion specificity, using our model. We also discuss the DNA-histone disassembly/assembly reaction modeled as a competition of two polyanions for binding to a polycation.