Peyrin E, Guillaume Y C, Guinchard C
Laboratoire de Chimie Analytique, Faculté de Medecine et Pharmacie, Bésançon, France.
Anal Chem. 1998 Oct 15;70(20):4235-40. doi: 10.1021/ac980370u.
Recently, a theoretical model was proposed to study the existence of pockets of acetonitrile (ACN) called clusters in a hydroorganic mixture. The proposal used ACN as an interaction organic modifier between D,L-dansyl amino acids and their binding site in human serum albumin at site II. This solute binding is governed by primary and secondary interactions. The primary interactions are under the dependence of the solute solvation by ACN clusters and electrostatic interactions. Following this first step, the solute engages strong short-range interactions with the residues of site II. Using a biochromatographic approach, the solute binding, i.e., the solute retention, was divided into two dielectric constant (epsilon) ranges. In the first range, epsilon > epsilon c (epsilon c is the critical dielectric constant); the primary and secondary nonstereoselective electrostatic interactions were the major contributions to the variation in the solute binding with the ACN fraction in the mixture. In the second range, epsilon < epsilon c, the solute retention variation with the ACN fraction was governed by its solvation by the ACN clusters and also by the secondary hydrophobic stereoselective interaction. The mathematical model developed provided the determination of the surface charge density of site II as well as the cluster number that solvates each solute.
最近，有人提出了一个理论模型来研究在水-有机混合物中被称为簇的乙腈（ACN）口袋的存在情况。该模型将ACN用作D，L-丹磺酰氨基酸与其在人血清白蛋白II位点的结合位点之间的相互作用有机修饰剂。这种溶质结合受一级和二级相互作用的支配。一级相互作用取决于ACN簇对溶质的溶剂化作用以及静电相互作用。在这第一步之后，溶质与II位点的残基发生强烈的短程相互作用。使用生物色谱方法，溶质结合，即溶质保留，被分为两个介电常数（ε）范围。在第一个范围内，ε>εc（εc是临界介电常数）；一级和二级非立体选择性静电相互作用是溶质与混合物中ACN分数结合变化的主要贡献因素。在第二个范围内，ε<εc，溶质保留随ACN分数的变化受ACN簇对其的溶剂化作用以及二级疏水立体选择性相互作用的支配。所开发的数学模型提供了II位点表面电荷密度以及溶剂化每个溶质的簇数量的测定方法。
