Peyrin E, Guillaume Y C, Guinchard C
Laboratoire de Chimie Analytique, Faculte de Medecine et Pharmacie, Place St. Jacques, 25030 Besancon Cedex, France.
Biophys J. 1999 Sep;77(3):1206-12. doi: 10.1016/S0006-3495(99)76972-9.
Chiral recognition mechanism relationships for binding at site II on human serum albumin (HSA) were investigated using D, L dansyl amino acids. Sodium phosphate salt was used as a solute-HSA interaction modifier. A new model was developed using a biochromatographic approach to describe the variation in the transfer equilibrium constant with the salt concentration, i.e., the nature of the interactions. The solute binding was divided into two salt concentration ranges c. For the low c values, below 0.03 M, the nonstereoselective interactions constituted the preponderant contribution to the variation in the solute binding with the salt concentration. For the high c values, above 0.03 M, the solute binding was governed by the hydrophobic effect and the stereoselective interactions. The different contributions implied in the binding process provided an estimation of both the surface charge density (sigma/F) and the surface area of the site II binding cavity accessible to solvent, which were found to be equal to around 10.10(-7) mol/m(2) and 2 nm(2). As well, the excess of sodium ions excluded by the solute transfer from the surface area of the pocket were about(-0.7) for dansyl norvaline and (-0.8) for dansyl tryptophan.
使用D、L-丹磺酰氨基酸研究了在人血清白蛋白（HSA）位点II上结合的手性识别机制关系。磷酸钠盐用作溶质-HSA相互作用调节剂。采用生物色谱方法建立了一个新模型，以描述转移平衡常数随盐浓度的变化，即相互作用的性质。溶质结合分为两个盐浓度范围c。对于低c值，低于0.03 M，非立体选择性相互作用对溶质结合随盐浓度变化的贡献占主导。对于高c值，高于0.03 M，溶质结合受疏水效应和立体选择性相互作用支配。结合过程中不同的贡献提供了对位点II结合腔可被溶剂接触的表面电荷密度（σ/F）和表面积的估计，发现其分别约为10×10⁻⁷ mol/m²和2 nm²。同样，对于丹磺酰正缬氨酸，溶质转移从口袋表面积排除的过量钠离子约为（-0.7），对于丹磺酰色氨酸约为（-0.8）。
