Rigorous estimation of effective protein charge from experimental electrophoretic mobilities for proteomics analysis using microchip electrophoresis
Rigorous estimation of effective protein charge from experimental electrophoretic mobilities for proteomics analysis using microchip electrophoresis
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DOI：
10.1016/j.colsurfa.2007.12.046
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发表时间：
2008-04-01
影响因子：
5.2
通讯作者：
Lee, Intaek
中科院分区：
文献类型：
--
作者：
Chun, Myung-Suk;Lee, Intaek
了解蛋白质的电泳率和Zeta电位是蛋白质组学研究中的一个重要问题。通过探索静电和电动原理，我们提出了一个框架，可以严格解释高电荷条件下保持整个缓冲pH范围的表面Zeta电位和有效电荷。根据非线性Poisson-Boltzmann方程，结合考虑Henry公式和德拜-休克尔阿萨茨公式的解析表达式，从球形粒子的电泳率积分表达式出发，计算了蛋白质表面的Zeta电势。随后，根据电势分布与表面电荷的对应关系计算了蛋白质的有效电荷，并考虑了双电层的存在。应用微芯片电泳法，对含有牛血清白蛋白和卵清蛋白的模型蛋白在不同pH缓冲溶液中的迁移率进行了实验研究。为了说明我们的考虑的有用性，还包括了文献中可用的电泳迁移率的实验数据。显然，线性关联的结果被认为高估了Zeta势，而低估了有效电荷。当Zeta电位小于25.69 mV时，线性关联和非线性关联之间的差异很小，但随着Zeta电位绝对值的增加，线性关联和非线性关联之间的差异相当大。(C)2008爱思唯尔B.V.保留所有权利。
Understanding of electrophoretic mobility and zeta potential is an important issue in charge characteristics of proteins for proteomics research. By exploring the electrostatic and electrokinetic principles, we presented a framework that would allow rigorous interpretations of surface zeta potential and effective charge for highly charged conditions holding the full range of buffer pH. Together with an analytic expression by considering the Henry's formula with Debye-Huckel ansatz, the zeta potential at the protein surface was evaluated from an integral expression for the electrophoretic mobility of a spherical particle on the basis of nonlinear Poisson-Boltzmann equation. Subsequently, the effective protein charge was evaluated from the corresponding relationships between potential distribution and surface charge, with accounting for the presence of an electric double layer. Applying the microchip electrophoresis, the experimental results of mobility data were obtained for model proteins with bovine serum albumin and ovalbumin in different pH of buffer solution. To illustrate the usefulness of our considerations, experimental data of electrophoretic mobility available in the literature are also included. It is evident that the results by linear correlations are identified to overestimate the zeta potential, while they underestimate the effective charge. The discrepancy between linear and nonlinear correlations is trivial for the zeta potential less than 25.69 mV, however, it fairly increases with increasing the absolute value of zeta potential. (C) 2008 Elsevier B.V. All rights reserved.