Analysis of the Statistical Thermodynamic Model for Nonlinear Binary Protein Adsorption Equilibria
Analysis of the Statistical Thermodynamic Model for Nonlinear Binary Protein Adsorption Equilibria
复制标题
非线性二元蛋白质吸附平衡统计热力学模型分析
DOI：
10.1021/bp070092x
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发表时间：
2007
影响因子：
2.9
通讯作者：
Y. Sun
中科院分区：
文献类型：
--
作者：
Xiaopeng Zhou;Xueli Su;Y. Sun
采用统计热力学（ST）模型研究了蛋白质在阴离子交换剂上的非线性二元吸附平衡。通过在pH 7.40下含有特定NaCl浓度（0.05、0.10和0.15 M）的10 mM Tris-HCl缓冲液中进行批吸附实验，测定了牛血红蛋白（Hb）和牛血清白蛋白（BSA）在DEAE Spherodex M上的单组分和二元蛋白吸附等温线。发现ST模型很好地描述了离子强度对单组分平衡的影响，模型参数取决于离子强度。此外，ST模型通过拟合的单组分模型参数对二元吸附数据进行了可接受的拟合，从而估计了二元ST模型参数。用静电学和热力学理论解释了离子强度对模型参数的影响。两类模型参数可分别计算吸附相蛋白质的有效电荷，且两种方法所得值一致。结果表明，ST模型用于描述非线性二元蛋白质吸附平衡的效用。
The statistical thermodynamic (ST) model was used to study nonlinear binary protein adsorption equilibria on an anion exchanger. Single‐component and binary protein adsorption isotherms of bovine hemoglobin (Hb) and bovine serum albumin (BSA) on DEAE Spherodex M were determined by batch adsorption experiments in 10 mM Tris‐HCl buffer containing a specific NaCl concentration (0.05, 0.10, and 0.15 M) at pH 7.40. The ST model was found to depict the effect of ionic strength on the single‐component equilibria well, with model parameters depending on ionic strength. Moreover, the ST model gave acceptable fitting to the binary adsorption data with the fitted single‐component model parameters, leading to the estimation of the binary ST model parameter. The effects of ionic strength on the model parameters are reasonably interpreted by the electrostatic and thermodynamic theories. The effective charge of protein in adsorption phase can be separately calculated from the two categories of the model parameters, and the values obtained from the two methods are consistent. The results demonstrate the utility of the ST model for describing nonlinear binary protein adsorption equilibria.