Adsorption of biopolymer at solid-liquid interfaces. 1. Affinities of DNA to hydrophobic and hydrophilic solid surfaces
Adsorption of biopolymer at solid-liquid interfaces. 1. Affinities of DNA to hydrophobic and hydrophilic solid surfaces
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DOI：
10.1021/la970686h
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发表时间：
1999-10-12
期刊：
影响因子：
3.9
通讯作者：
Chattoraj, DK
中科院分区：
文献类型：
--
作者：
Gani, SA;Mukherjee, DC;Chattoraj, DK
从水溶液中的DNA在不同的疏水性和亲水性固体表面上的吸附程度（γ（2）（1））作为pH值，温度，介质的离子强度和变性剂的函数进行了比较。在一个给定的表面（除葡聚糖凝胶）上的γ（2）（1）随DNA的核苷酸浓度（X-2）（以摩尔分数为单位）的增加而增加，但当X-2达到X-2（m）时，γ（2）（m）达到一个单层饱和值。在大多数情况下，当X-2 >> X-2（m）时，Gamma（2）（1）进一步增加。各种中性电解质如LiCl、KCl、CsCl、KBr、CaCl_2和Na_2SO_4，表面活性剂如SDS和Triton-X 100，热变性作用以及酸和碱的加入在研究炭粉对DNA的吸附过程中起着重要作用。此外，已经进行了比较研究，以检查DNA对不同类型的固体表面的相对亲和力。不同类型的表面在控制吸附过程中的重要作用已被解释在吉布斯的表面过剩量。实验结果已被解释的最大工作方面，由于DNA吸附在各种固体表面上的自由能变化和更定量的标准自由能变化（Δ G度）的DNA的饱和度的表面作为一个结果的变化，在散装的核苷酸浓度从零到统一的摩尔分数单位。
The extent of adsorption (Gamma(2)(1)) of DNA from aqueous solution on different hydrophobic and hydrophilic solid surfaces has been compared as a function of pH, temperature, ionic strength of the medium, and denaturants. Gamma(2)(1) at a given surface (except sephadex) increases with an increase of the nucleotide concentration (X-2) of DNA in mole fraction units, but it-attains a monolayer saturation value Gamma(2)(m) when X-2 attains a value X-2(m). In most cases Gamma(2)(1) increases further when X-2 >> X-2(m). Various neutral electrolytes like LiCl, KCl, CsCl, KBr, CaCl2, and Na2SO4, surfactants like SDS and Triton-X 100, the denaturing action of heat, and the addition of acid and alkali have been observed to play an important role during the study of the adsorption of DNA on charcoal powder. Further, a comparative study has been performed to examine the relative affinity of DNA toward different types of solid surfaces. The significant role of different types of surfaces in controlling the adsorption process has been explained in terms of Gibbs' surface excess quantities. The experimental results have been interpreted in terms of maximum work due to the free energy change of DNA adsorption on various solid surfaces and more quantitatively in terms of the standard free energy change (Delta G degrees) for the saturation of the surface by DNA as a result of the change in the nucleotide concentration in the bulk from zero to unity in mole fraction units.