用参数Z表征疏水色谱中脲浓度与蛋白质分子的构象变化

An Investigation of the Relationship Between Concentration of Urea and Molecular Conformation of Biopolymers in Hydrophobic Interaction Chromatography by Using a Characterization Parameter Z

研究了５种标准蛋白在流动相中含有不同脲浓度条件下的疏水色谱保留行为。当脲 浓度不变时，蛋白质的保留仍然服从计量置换保留模型，并可测定在该特定脲浓度条件下蛋白质的Ｚ值。计量置换参数Ｚ可作为疏水色谱中生物大分子构象变化的表征。蛋白质的Ｚ值随脲浓度的增大而减小。除分子构象变化的因素外，Ｚ值变化与脲参与置换剂分子间的计量置换过程有关。Ｚ值变化的连续性与否直接反映了蛋白质分子构象的连续性变化或突变。

The retention behavior of five proteins in hydrophobic interaction chromatography (HIC) under the mobile phase of (NH4)2SO4-KH2PO4 containing various urea concentrations was investigated. It was found that the retention of these proteins follow the stoichiometric displacement model for retention (SDM-R), so long as the urea concentration remains con- stant in the mobile phase. The Z values of these proteins in HIC can be used as a characteri- zation parameter of the change in the molecular conformation of these proteins. The Z values of these proteins decrease with the increasing concentration of urea in the mobile phase. Be- sides molecular con formation, the changes in the Z values of these proteins may also be caused from the participation of urea in the stoichiometric displacement process between pro- tein and the displacing agent molecules. Whether the change in the Z valt1es is continuous or not, it reflects the same change tendency in the molecular conformation of proteins.