作为聚电解质的双链DNA的性质
PROPERTIES OF DOUBLE-STRANDED DNA AS A POLYELECTROLYTE.
作者信息
OHNISHI T
出版信息
Biophys J. 1963 Nov;3(6):459-68. doi: 10.1016/s0006-3495(63)86831-9.
The stability of the structure of double-stranded DNA in the salt-free solution is discussed on the basis of the polyelectrolyte theory. Assuming that DNA is an infinitely long rod, and the formation of double strands is divided into combining process and folding process, the free energy changes required in these processes are calculated by the use of the exact solutions of two-dimensional Poisson-Boltzmann equation for the one rod and the two rod systems.By strong depression of electrostatic interaction due to counter-ion condensation phenomena, the free energy change is remarkably decreased so that the double-stranded structure of DNA can be stabilized by energy of hydrogen bonds between base pairs. The increase of the activity coefficient of a counterion upon heat denaturation of DNA is also explained.
基于聚电解质理论，讨论了无盐溶液中双链DNA结构的稳定性。假设DNA是无限长的棒状分子，双链的形成分为结合过程和折叠过程，利用一维和二维棒状体系的二维泊松-玻尔兹曼方程的精确解，计算了这些过程所需的自由能变化。由于反离子凝聚现象导致静电相互作用的强烈降低，自由能变化显著减小，从而使DNA的双链结构可以通过碱基对之间的氢键能量得以稳定。同时也解释了DNA热变性时反离子活度系数的增加。
Zotero 插件