A comprehensive Brownian Dynamics approach for the determination of non-ideality parameters from analytical ultracentrifugation.
A comprehensive Brownian Dynamics approach for the determination of non-ideality parameters from analytical ultracentrifugation.
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DOI：
10.1021/acs.langmuir.9b01916
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
M. Uttinger;S. Wawra;Tobias Guckeisen;J. Walter;Andreas Bear;T. Thajudeen;P. Sherwood;Ana-S Smith;A. Wagemans;W. Stafford;W. Peukert
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文献类型：
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作者：
M. Uttinger;S. Wawra;Tobias Guckeisen;J. Walter;Andreas Bear;T. Thajudeen;P. Sherwood;Ana-S Smith;A. Wagemans;W. Stafford;W. Peukert
布朗动力学（BD）已被应用作为一个全面的工具来模拟分析超离心（AUC）实验中的纳米粒子的沉降和扩散。在本文中，我们通过考虑空间相关扩散和溶剂可压缩性来扩展BD算法。由此，准确地考虑了在增加的压力下由改变的溶剂性质引起的沉降和扩散系数的变化。此外，它演示了如何空间依赖性扩散的概念来描述浓度依赖性的沉降和扩散系数，特别是通过Gralen系数和第二维里系数。热力学非理想性对扩散性质的影响可以准确地模拟，并与众所周知的评估工具一致。BD模拟沉降平衡和沉降速度AUC实验，包括流体动力学和热力学非理想性的影响进行了验证，在SEDANAL的全球评估。溶剂的可压缩性和检索的非理想参数的相互作用可以利用BD进行研究。最后，从沉降速度AUC实验和BD模拟和膜渗透压测定法相比，确定溶菌酶的第二维里系数。这些结果符合DLVO理论。总之，BD模拟建立了AUC的非理想沉降的验证提供了一个良好的基础，即使在多分散系统中的复杂的相互作用的评估。
Brownian Dynamics (BD) has been applied as a comprehensive tool to model sedimentation and diffusion of nanoparticles in analytical ultracentrifugation (AUC) experiments. In this manuscript, we extend the BD algorithm by considering space-dependent diffusion and solvent compressibility. With this, the changes in the sedimentation and diffusion coefficient from altered solvent properties at increased pressures are accurately taken into account. Moreover, it is demonstrated how the concept of space-dependent diffusion is employed to describe concentration-dependent sedimentation and diffusion coefficients in particular through the Gralen coefficient and the second virial coefficient. The influence of thermodynamic non-ideality on diffusional properties can be accurately simulated and agree with well-known evaluation tools. BD simulations for sedimentation equilibrium and sedimentation velocity AUC experiments including effects of hydrodynamic and thermodynamic non-ideality are validated by global evaluation in SEDANAL. The interplay of solvent compressibility and retrieved non-ideality parameters can be studied utilizing BD. Finally, the second virial coefficient is determined for lysozyme from sedimentation velocity AUC experiments and BD simulations and compared to membrane osmometry. These results are in line with DLVO theory. In summary, BD simulations are established for the validation of non-ideal sedimentation in AUC providing a sound basis for the evaluation of complex interactions even in polydisperse systems.