Hydrodynamic and Polyelectrolyte Properties of Actin Filaments: Theory and Experiments.
Hydrodynamic and Polyelectrolyte Properties of Actin Filaments: Theory and Experiments.
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作者：
肌动蛋白丝的聚电解质特性、流体动力学特性、与生物环境的相互作用、外加力场对其在真核细胞过程中的生物活性起着至关重要的作用。在本文中，我们介绍了一种独特的方法，结合动力学和电泳光散射实验，扩展的半柔性蠕虫状链模型，以及不对称聚合物长度分布理论来表征肌动蛋白细丝在水溶液中的聚电解质和流体动力学特性。采用拟合方法对理论和细丝模型进行了优化。我们使用相同的样品和实验条件，并考虑了几种g-肌动蛋白和聚合缓冲液，以阐明它们的化学成分、还原剂、pH值和离子强度对丝平移扩散系数、电泳迁移率、结构因子、不对称长度分布、有效丝直径、电荷、zeta电位和半柔韧性的影响。与分子结构模型得到的结果相比，我们的结果显示，由于在纤维周围形成了双电解质层，g -肌动蛋白有效电荷的值更低，而有效纤维直径的值更显著。与通常从电子显微图中报道的数据相反，我们的结果中持续长度和平均轮廓长度的值较低，这与丝端向亚微长度转移的关联率的显著差异一致，亚微长度是长度分布的最大值。
Actin filament’s polyelectrolyte and hydrodynamic properties, their interactions with the biological environment, and external force fields play an essential role in their biological activities in eukaryotic cellular processes. In this article, we introduce a unique approach that combines dynamics and electrophoresis light-scattering experiments, an extended semiflexible worm-like chain model, and an asymmetric polymer length distribution theory to characterize the polyelectrolyte and hydrodynamic properties of actin filaments in aqueous electrolyte solutions. A fitting approach was used to optimize the theories and filament models for hydrodynamic conditions. We used the same sample and experimental conditions and considered several g-actin and polymerization buffers to elucidate the impact of their chemical composition, reducing agents, pH values, and ionic strengths on the filament translational diffusion coefficient, electrophoretic mobility, structure factor, asymmetric length distribution, effective filament diameter, electric charge, zeta potential, and semiflexibility. Compared to those values obtained from molecular structure models, our results revealed a lower value of the effective G-actin charge and a more significant value of the effective filament diameter due to the formation of the double layer of the electrolyte surrounding the filaments. Contrary to the data usually reported from electron micrographs, the lower values of our results for the persistence length and average contour filament length agree with the significant difference in the association rates at the filament ends that shift to sub-micro lengths, which is the maximum of the length distribution.
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影响因子：
4.4
作者：
Li, GL;Wen, Q;Tang, JX
通讯作者：
Tang, JX
DOI：
10.1007/s00249-007-0236-1
发表时间：
2008-04-01
影响因子：
2
作者：
Haviv, Lior;Gov, Nir;Bernheim-Groswasser, Anne
通讯作者：
Bernheim-Groswasser, Anne
影响因子：
4.4
作者：
DEGENNES, PG
通讯作者：
DEGENNES, PG
影响因子：
3.4
作者：
Kas, J;Strey, H;Janmey, PA
通讯作者：
Janmey, PA
影响因子：
3.4
作者：
LANNI, F;WARE, BR
通讯作者：
WARE, BR