Dynamic Light Scattering Application to Study Protein Interactions in Electrolyte Solutions
Dynamic Light Scattering Application to Study Protein Interactions in Electrolyte Solutions
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动态光散射应用研究电解质溶液中的蛋白质相互作用
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Junfeng Li
中科院分区：
文献类型：
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作者：
Shaoxin Li;D. Xing;Junfeng Li
悬浮在溶液中的颗粒的扩散系数的浓度依赖性主要取决于占据的体积分数以及排斥力和吸引力。这种依赖性由相互作用参数表示，该参数可以通过光散射测量进行实验评估，并且已在本工作中确定了不同盐浓度条件下 BSA 的扩散系数。结果表明，蛋白质的扩散系数随着蛋白质浓度的增加而增大，而当离子强度逐渐增大时，扩散系数随着蛋白质浓度的增加而减小。 BSA 扩散系数的浓度依赖性在平均力的二体势的背景下进行解释，其中包括排斥硬球和库仑相互作用以及吸引色散。随着离子强度的增加，德拜屏蔽减少，蛋白质相互作用从排斥变为吸引，蛋白质开始聚集。通过BSA扩散系数的浓度依赖性，可以获得蛋白质相互作用的参数，可以发现蛋白质的净有效电荷为-9.0 e，Hamaker常数为2.8kBT。这项工作表明 DLS 是研究蛋白质相互作用的有效技术。
The concentration dependence of the diffusion coefficient of particles suspended in solution depends primarily on the occupied volume fraction and on repulsive and attractive forces. This dependency is expressed by the interaction parameter, which can be assessed experimentally by light scattering measurements and have been determined for the diffusion coefficient of BSA under different salt concentration conditions in the present work. The result shows that the diffusion coefficient of protein grows up with increasing protein concentration, and when the ionic strength turns up gradually the diffusion coefficient decreases with protein concentration’s increasing. The concentration dependence of BSA diffusion coefficients is interpreted in the context of a two-body potential of mean force, which includes repulsive hard-sphere and Coulombic interactions and attractive dispersion. With the increase of ionic strength, Debye screening decreases, protein interaction changes from repulsion to attraction, and protein begins to aggregate. By means of the concentration dependence of BSA diffusion coefficients, one can obtain the parameters of protein interactions and can find that protein bears a net effective charge of −9.0 e and has a Hamaker constant of 2.8kBT. This work demonstrates that DLS is an effective technique of studying protein interactions.