Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
J Chromatogr A. 2010 Aug 20;1217(34):5492-500. doi: 10.1016/j.chroma.2010.06.055. Epub 2010 Jul 1.
Experiments with human serum albumin on a strong cation exchange resin exhibit a peculiar elution pattern: the protein elutes with two peaks in a modifier gradient. This behavior is modeled with a general rate model, where the two elution peaks are modeled with two binding conformations, one of which is at equilibrium conditions, while for the other, the adsorption process is rate limited. Isocratic experiments under nonadsorbing conditions were used to characterize the mass transfer process. The isotherm of both adsorption conformations as well as the kinetic of adsorption and desorption for the second conformation are functions of the modifier concentration. They are evaluated with linear modifier gradient experiments and step experiments with various adsorption times. All experimental features are well reproduced by the proposed modified general rate model.
在修饰梯度中，蛋白质以两个峰洗脱。这种行为可以用一般速率模型来模拟，其中两个洗脱峰用两种结合构象来模拟，其中一种处于平衡条件下，而对于另一种，吸附过程受到速率限制。在非吸附条件下进行的等度实验用于表征传质过程。两种吸附构象的等温线以及第二种构象的吸附和解吸动力学都是修饰剂浓度的函数。它们通过线性修饰梯度实验和具有不同吸附时间的阶跃实验进行评估。所有实验特征都可以通过所提出的改进的一般速率模型很好地再现。
