通过动态光散射技术揭示的肌动蛋白分子间相互作用。

Intermolecular interaction of actin revealed by a dynamic light scattering technique.

作者信息

Kanzaki Noriko, Uyeda Taro Q P, Onuma Kazuo

机构信息

Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology, Higashi 1-1-1, Central 6, Tsukuba 305-8566, Japan.

出版信息

J Phys Chem B. 2006 Feb 16;110(6):2881-7. doi: 10.1021/jp054865g.

DOI:10.1021/jp054865g

PMID:16471898

Abstract

The intermolecular interaction force of actin was studied by a dynamic light scattering technique. The mutual diffusion coefficients (D) of monomeric actin were accurately determined in a G-buffer with a low concentration of KCl from 0 to 10 mM. The translational diffusion coefficient was obtained as D(0) = (87 +/- 3) x 10(-12) m(2).s(-1) at 25 degrees C and pH 7.4, which gives a hydrodynamic radius of monomeric actin of r(H) = 2.8 +/- 0.1 nm. The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, assuming electrostatic and van der Waals potentials, failed to describe the change in interaction parameter (lambda) with KCl concentration, but the extended DLVO theory succeeded if an additional repulsive potential was assumed. The Hamaker constant of actin in the Ca(2+)-ATP bound state was determined for the first time as A(H) = 10.4 +/- 0.6 k(B)T.

摘要

通过动态光散射技术研究了肌动蛋白的分子间相互作用力。在KCl浓度为0至10 mM的低浓度G缓冲液中，精确测定了单体肌动蛋白的互扩散系数（D）。在25℃和pH 7.4条件下，得到的平动扩散系数为D(0) = (87 +/- 3) x 10(-12) m(2).s(-1)，由此得出单体肌动蛋白的流体力学半径为r(H) = 2.8 +/- 0.1 nm。假设存在静电和范德华势的Derjaguin-Landau-Verwey-Overbeek（DLVO）理论未能描述相互作用参数（λ）随KCl浓度的变化，但如果假设存在额外的排斥势，则扩展的DLVO理论成功。首次确定了Ca(2+)-ATP结合状态下肌动蛋白的哈梅克常数为A(H) = 10.4 +/- 0.6 k(B)T。