Electrostatic and van der Waals contributions to protein adsorption: computation of equilibrium constants
Electrostatic and van der Waals contributions to protein adsorption: computation of equilibrium constants
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DOI：
10.1021/la00028a015
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发表时间：
1993-04
期刊：
影响因子：
3.9
通讯作者：
Charles M. Roth;A. Lenhoff
中科院分区：
文献类型：
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作者：
Charles M. Roth;A. Lenhoff
虽然蛋白质吸附已被大量描述和利用，但很少有人致力于开发其先验预测的模型。在这里，我们描述了一种方法，允许计算蛋白质表面平衡常数（即，平衡atlow surfacecoverages）的基础上蛋白质分子结构和表面性质。该模型的关键是计算的静电和货车德瓦尔斯能量之间的相互作用的胶体蛋白质分子和一个平面，带电荷的表面在一个固定的距离和方向相对于it. Results蛋白质溶菌酶，然而，这些计算是非常耗时的。因此，我们利用一个简单的描述蛋白质作为一个低介电球体，其净电荷放置在中心。由于盐交换对静电相互作用的强烈影响，它特别用于计算与离子交换色谱法相关的离子强度和#n之间的关系。影响平衡常数值的物理性质是蛋白质和表面净电荷，Hamaker常数和蛋白质大小;前两个影响静电相互作用，第三个表征分散力，最后一个影响两种类型的相互作用。除了允许吸附平衡的先验预测，本文提出的结构可以允许更好地理解和解释蛋白质吸附的静电和分散机制。
Although protein adsorption has been much described and exploited, little effort has been directed toward the development of models for its a priori prediction. Here we describe a methodology that allows for the computation of protein-surface equilibrium constants(ie, equilibria atlow surfacecoverages) based on protein molecular structure and surface properties. The crux of the model is the computation of the electrostatic and van der Waals energies of interaction between a colloidal protein molecule and a planar, charged surface at a fixed distance from and orientation with respect to it. Results for the protein lysozyme are presented; however, these calculations are computationally very time-intensive. Consequently, we utilize a simplified description of the protein as a low dielectric sphere with its net charge placed at the center. It is used in particular to compute the relationship, relevant to ion-exchange chromatography, between ionic strength and#«,, due to the strong effect which saltexerts on electrostatic interactions. The physical properties that affect the value of the equilibrium constant are protein and surface net charges, Hamaker constant, and protein size; the first two influence electrostatic interactions, the third characterizes dispersion forces, and the last affects both types of interactions. In addition to allowing a priori prediction of adsorption equilibria, the construct presented in this paper can allow for improved understanding and interpretation of electrostatic and dispersive mechanisms for protein adsorption.